Must-Know Details About STAYC Kpop Members: Names, Ages & More

STAYC Kpop's debut single "So Bad" captured 2.6 million views within just 24 hours of its release, marking an impressive entrance into the K-pop scene.

Notably, the six-member group, formed by hit-making producer duo Black Eyed Pilseung, took three years of careful planning before their official debut on November 12, 2020. Since then, STAYC has released 19 albums and earned 21 awards, establishing themselves as a powerhouse in the industry.

The group, consisting of members Sumin, Sieun, Isa, Seeun, Yoon, and J, ranges in age from 20 to 24 years old (2024). Under the leadership of co-leaders Sieun and Seeun as of August 2023, STAYC continues to shape their unique position in K-pop with their latest release, their first studio album "Metamorphic" in July 2024.

How STAYC Formed: From HighUp Girls to Kpop Icons

Initially known as "High Up Girls," STAYC began its journey long before stepping into the spotlight. Prior to their official debut, the group appeared in YouTube Originals docuseries "K-Pop Evolution" (March 2021), which provided rare insights into their formation process, despite being released months after their debut.

STAYC's pre-debut journey

The documentary revealed that in late 2019, High Up Entertainment was finalizing their girl group from eight remaining trainees. The members faced uncertainty as their planned debut had been postponed multiple times. During monthly evaluations, the trainees performed covers including Twice's "Like Ooh-Aah" and a pivotal performance of Red Velvet's "Psycho" that ultimately determined the final lineup.

High Up Entertainment's official introduction of the group began on September 8, 2020, when they announced their plans to debut their first girl group in the second half of the year. The members were revealed in stages:

September 8: Sieun announced as the first member
September 9: Sumin and Seeun revealed as second and third members
October 7: Announcement that the group would consist of six members with a November debut
October 12: Official reveal of the group name "STAYC"
October 13-15: Introduction of all members in order: Sumin, Yoon, Sieun, Isa, Seeun, and J

On October 23, 2020, the company released an official scheduler announcing STAYC would debut on November 12 with their first single album "Star To A Young Culture".

The meaning behind the name STAYC

The name STAYC stands for "Star To A Young Culture," reflecting the group's aim to lead youth culture and dominate pop culture. According to company materials, STAYC aspires to "grow into a star that leads the young culture" and become the "Future of K-pop".

Furthermore, the group was intentionally developed around the concept of being "healthy" from their pre-debut process. High Up Entertainment focused on fostering good personality traits and healthy mindsets among members, aiming to create idols the public could trust and love.

The role of Black Eyed Pilseung in their formation

Black Eyed Pilseung, the renowned production duo behind hits like Sistar's "Touch My Body," Twice's "TT," and Chungha's "Roller Coaster," played a pivotal role in STAYC's creation. Not merely producers, they are co-founders of High Up Entertainment and actively managed the group's formation and development.

Interestingly, fate seemed to guide the group's creation. During an interview, Rado of Black Eyed Pilseung explained that "there were ups and downs and happy accidents" in forming STAYC. After struggling with traditional auditions, a turning point came when they were invited to a private audition at JYP Entertainment. There, they discovered Sieun, who was originally pursuing an acting career at JYPE.

Subsequently, a JYP staff member contacted Rado about meeting Sieun, a coincidence that Rado said "gave him shivers". A similar situation occurred with Yoon, who was also on an acting path before Rado recognized her musical potential.

The duo described STAYC's signature sound as "Teen Fresh," combining "Teen" and "Fresh" to highlight the members' unique vocal colors. Black Eyed Pilseung has composed almost every STAYC song, creating a distinctive sonic identity that would become central to the group's appeal.

Sumin: The Grounded Leader of STAYC

As the oldest member of STAYC, Bae Sumin brings mature stability to the group with her grounded personality and thoughtful demeanor. Her journey from trainee to idol showcases her dedication to the craft and resilience in the competitive K-pop industry.

Sumin's full name and birthday

Born Bae Su Min (배수민) in Pohang, South Korea, Sumin celebrated her birthday on March 13, 2001. Her stage name remains identical to her given name, maintaining simplicity and authenticity in her public identity. While some K-pop idols opt for completely different stage names, Sumin chose to keep her birth name, creating immediate recognition among fans.

She was officially revealed as the second member of STAYC on September 9, 2020, following Sieun's introduction the previous day. This strategic revelation built anticipation among K-pop enthusiasts about the upcoming group's composition and concept.

Sumin's age and zodiac sign

At 24 years old (as of 2025), Sumin is the eldest member of STAYC. Her zodiac sign is Pisces, characterized by empathy, intuition, and adaptability—traits that complement her leadership abilities. Pisces individuals are often known for their compassionate nature and artistic sensibilities, qualities that Sumin brings to her performances.

Born in Pohang, South Korea, she represents the traditional values often found in smaller Korean cities while embracing the modern entertainment landscape. Her background adds depth to STAYC's diverse member composition.

Sumin's MBTI and personality traits

Sumin's MBTI personality type is ISFJ, known as "The Defender". This personality type is characterized by warmth, responsibility, and practical attention to detail. ISFJs typically work efficiently behind the scenes without demanding recognition—a quality evident in Sumin's leadership style.

Interestingly, her fellow members voted her as both the cutest member and the biggest prankster in the group, revealing the duality in her personality. This combination of playfulness and reliability makes her approachable yet respected within the group dynamic.

Beyond her idol career, Sumin has varied interests that shape her character:

Her hobbies include polaroid photography, eating corn, and reading webtoons
If not an idol, she envisioned herself as an office worker who runs a cooking and mukbang YouTube channel on the side
Her motto reflects her grounded perspective: "Don't look at the trees, look at the forest"

Sumin's role in STAYC and leadership history

Sumin served as STAYC's first leader from their debut on November 12, 2020, until August 2023. Her extended training period of 5 years and 6 months provided her with the experience necessary to guide the newly-formed group during their crucial early years in the industry.

However, STAYC introduced a significant change to their leadership structure in 2023. On August 8, 2023, the group announced that Sieun and Seeun would take over as co-leaders. This transition marked a new chapter in STAYC's organizational approach, allowing Sumin to focus on her performance roles.

Currently, Sumin serves as a sub-vocalist and rapper within the group. While no longer in the official leadership position, her experience and influence continue to provide stability to the group dynamic. Her professional aspirations extend beyond STAYC—she has expressed interest in possible collaborations with international artists like Bebe Rexha or Max Schneider.

Musically influenced by global K-pop sensation BTS, whom she cites as her role models, Sumin incorporates their dedication and versatility into her own approach to music and performance. Additionally, she has expressed interest in befriending members of KARD and Girls' Generation, showing her appreciation for diverse musical styles within the K-pop industry.

Sieun: The Vocal Powerhouse with Star Roots

Park Si-eun stands out in STAYC kpop not only for her powerful vocals but also for her notable lineage as the daughter of famous 1980s Korean singer Park Nam-jung. This unique background has influenced her journey to becoming one of the group's most recognized talents.

Sieun's full name and background

Born Park Si-eun (박시은) on August 1, 2001, in Ichon-dong, Yongsan-gu, Seoul, South Korea, Sieun comes from a family with deep musical roots. Her English name is Rachel Park, providing an alternative for international fans. Moreover, she has a younger sister named Siwoo, completing her immediate family circle. Sieun attended several educational institutions throughout her formative years, including Seoul SinYongsan Elementary School, SangMyung Elementary School, SangMyung Middle School, and Goyang High School of Arts.

Her connection to music started early, likely influenced by her father's successful career. Nevertheless, she forged her own path in entertainment, ultimately enrolling in Chung-Ang University's Performance and Visual Creation Department in 2020, where she majors in Theatre.

Sieun's age and acting career before STAYC

At 23 years old (as of 2024), Sieun had already established herself as a respected child actress before joining STAYC. Her acting debut came in February 2014 through EBS's children's television series "Pluto Secret Society." In fact, her acting portfolio grew impressively with appearances in:

Popular dramas including "Signal," "The Good Wife," "Queen for Seven Days," and "The Crowned Clown"
Films such as "Love Forecast" and "Golden Slumber"
Award-winning performances, most notably winning the Youth Acting Award at the 2018 SBS Drama Awards for her role in "Still 17"

Sieun's entertainment journey took an interesting turn when she joined JYP Entertainment on January 18, 2017. Originally pursuing acting at JYP, she left the company in 2019 after JYP Actors became defunct. She subsequently signed with High Up Entertainment in December 2019, marking the beginning of her idol career after training for a total of 4 years.

Sieun's MBTI and leadership role

With an MBTI personality type of ENFJ (The Protagonist), Sieun embodies the warm, forthright characteristics typical of this personality. ENFJs are known as natural leaders with passion and charisma that inspire others. Coupled with their strong ideas and values, they possess creative energy to achieve their goals.

As well as her charismatic personality, Sieun's leadership capabilities were officially recognized when STAYC announced a new rotational leadership system on August 8, 2023. Under this structure, Sieun and Seeun were appointed as co-leaders, marking a significant evolution in the group's organization.

Sieun's vocal strengths and musical influence

Recognized as STAYC's main vocalist, Sieun has consistently demonstrated exceptional vocal abilities. Her clear voice, remarkable stability, and effortless high notes have become her signature strengths. For instance, she impressed fans with her cover of Ariana Grande's "Break Free," where she confidently belted a G5 note, showcasing her impressive vocal range.

IU serves as Sieun's primary musical influence and role model. She has expressed deep admiration for IU's sincerity with fans, care for those around her, and continuous self-improvement. Apart from IU, she has mentioned G-Dragon and Apink among her favorite artists.

Her technical prowess is complemented by emotional delivery, with many noting that her performances are characterized by the emotion she pours into her singing. In the group's vocal dynamic, Sieun handles the high notes while member J covers the low notes, creating a balanced sound that has become integral to STAYC's musical identity.

Sieun's motto reflects her thoughtful nature: "Let's love ourselves and see each other and give to each other. Let's cherish the present."

Isa: The Stylish Vocalist with a Warm Heart

With her distinct vocal tone and fashion-forward presence, Lee Chae Young, better known as Isa, adds a sophisticated element to STAYC's lineup. Unanimously voted by fellow members as the group's best dresser, Isa balances her stylish image with a nurturing personality that has earned her the nickname "mother of STAYC."

Isa's full name and birthday

Born Lee Chae Young (이채영) on January 23, 2002, Isa carries a stage name that represents her unique identity within the group. Interestingly, her stage name was originally planned to be "Lily" before the final decision settled on "Isa." She joined High Up Entertainment in March 2018, making her the first trainee to become part of what would later become STAYC kpop. She trained for approximately three years before the group's debut in November 2020.

Isa's age and hometown

At 23 years old (as of 2025), Isa proudly represents her hometown of Busan, specifically Millak-dong in the Suyeong-gu district. As an only child from Busan's Hak Enter Academy, she brings a distinctive regional perspective to the group. She has shared that her hobbies include searching for good restaurants, shopping, and discovering new places—activities that connect to her Busan roots where food culture and exploration are valued.

Isa's MBTI and personality

Isa's MBTI personality type is ESFJ, known as "The Consul." This personality type is characterized by being attentive, people-focused, and community-oriented. ESFJs make up about twelve percent of the population and are often described as popular figures who enjoy setting positive tones in social settings.

Her warm heart and high moral sense make her a natural confidant within the group. Other members frequently consult with her about their worries, reflecting her nurturing nature. Her personal motto—"Let's only look for the good things; let's only think of the good things"—perfectly captures her positive outlook on life.

Isa's role in STAYC and fashion sense

Within STAYC, Isa serves as a lead vocalist, bringing her distinctive vocal color to the group's "Teen Fresh" sound. Beyond her musical contributions, she has carved out a unique identity through her impeccable fashion sense. Her fellow members unanimously acknowledge her as the group's fashion leader, highlighting how precious her love for shopping is to their collective image.

Isa's style ranges from edgy outfits in music videos like "LIT" to elegant formal wear and casual-chic ensembles. Her fashion versatility includes:

Fusion of casual and formal styles (office wear with personal touches)
Edgy combinations like denim tops with camouflage skirts
Brand accessories such as Moschino beanies
Elegant summer dresses

Beyond fashion, Isa has shown interest in healthy lifestyles, particularly veganism. She has shared that she initially found veganism unfamiliar but grew interested in its environmental benefits and health advantages. This awareness extends to her animal-loving nature, although she is allergic to animal hair alongside numerous food allergies including beans, eggs, milk products, and several other items.

If she weren't pursuing a career as an idol, Isa has mentioned she would likely work in the fashion industry, further underscoring her passion for style and aesthetics.

Seeun: The Bright Spirit and Co-Leader

Bright smiles and gentle leadership define Yoon Seeun, whose warm presence brings balance to STAYC kpop. Known for her cheerful energy and impressive acting background, Seeun has evolved from child actress to K-pop idol with a unique blend of talent and approachability.

Seeun's full name and age

Born Yoon Se Eun (윤세은) on June 14, 2003, Seeun is currently 21 years old (as of 2024). A Gemini by zodiac sign, she stands at 167 cm (5'6") tall. Hailing from Pyeongtaek, Gyeonggi, South Korea, Seeun comes from a close-knit family with an older sister and younger brother. Her stage name remains identical to her birth name, maintaining authenticity in her public identity. Besides her musical talents, Seeun possesses unique skills including playing the flute and running.

Seeun's MBTI and charming traits

Seeun's MBTI personality type is INFP, known as "The Mediator". This personality type characterizes her as quiet, open-minded, and imaginative with vibrant inner life. INFPs typically possess deep emotional responses to music, art, and people around them, explaining Seeun's creative nature.

Among her most distinctive traits, Seeun's smile stands out as her defining charming point. Within STAYC, she's officially "in charge of aegyo" (cute expressions and behaviors), bringing lighthearted energy to the group. Besides performing, Seeun enjoys collecting stickers and crafting miniature houses. Her personal motto reflects her thoughtful nature: "When I achieve my dreams, I'll become someone else's dream".

Seeun's leadership role and group dynamics

In a significant shift for STAYC, Seeun and Sieun were appointed co-leaders on August 8, 2023, replacing Sumin who had led since debut. This change came after the group announced a new rotational leadership system on April 1, 2023, where different members would serve as leaders for each comeback.

Regarding group dynamics, Seeun reportedly gets along best with Yoon. Currently, she shares a room with Isa in the group's dorm, yet earlier reports suggested she shared space with Sieun, Isa, and J, indicating possible dorm reorganization. Interestingly, Seeun mentioned that if she became a drama scriptwriter, she would cast J as the female lead.

Seeun's pre-debut acting experience

Before joining High Up Entertainment in 2019, Seeun worked as a child actress under Kiana Entertainment. Her acting credits include appearances in notable shows like "The Guardians" and "Circle". This background in acting helped develop her performance skills and camera presence.

Seeun's pre-idol journey included trainee periods at both Plan A Entertainment and Play M Entertainment. Additionally, she was a former pre-debut member of Play M Girls, which later became the girl group Weeekly. After joining High Up Entertainment, she trained for approximately 2 years and 7 months before debuting with STAYC.

Yoon: The Energetic Vocalist with Global Appeal

Towering above her fellow members at 172.6 cm (5'8"), Shim Ja Yoon brings vibrant energy and international charisma to STAYC kpop. Known for her striking visuals and powerful stage presence, she has quickly become a fan favorite across global audiences.

Yoon's full name and birthday

Born Shim Ja Yoon (심자윤) on April 14, 2004, in Gwanju, Jeolla-do, South Korea, Yoon carries the English name Nicole. Her stage name simply uses the last syllable of her given name, creating a memorable one-syllable identifier. Officially introduced as a STAYC member on October 15, 2020, Yoon completed the group's lineup alongside Sumin, Sieun, Isa, Seeun, and J.

Yoon's age and height

At 21 years old (as of 2025), Yoon holds the distinction of being the tallest member in STAYC at 172.6 cm (5'8"). Her blood type is A, and she was born under the Aries zodiac sign, often associated with dynamic energy and leadership qualities. Interestingly, Yoon and Isa attended the same high school, occasionally borrowing each other's uniforms, which created a bond before their debut.

Yoon's MBTI and favorite artists

Regarding personality types, Yoon shows versatility with reports of both ENFP (The Campaigner) and ENTP (The Debater) MBTI types. The ENTP personality describes her as "bold and creative" who "pursues goals vigorously despite resistance." Alternatively, as an ENFP, she exhibits enthusiasm and authenticity.

Musically, Yoon draws inspiration from diverse artists:

BLACKPINK's Lisa serves as her primary role model
She deeply admires (G)I-DLE, once crying after meeting them
Red Velvet and GFriend rank among her favorite groups
She has expressed interest in collaborating with Little Mix or (G)I-DLE

Yoon's international fanbase and charisma

Nicknamed "Barbie Doll" and "Baby Tiger," Yoon's charm transcends cultural boundaries. Throughout STAYC's European tour, particularly in London, she connected meaningfully with international fans. After a brief visit to Notting Hill during filming, she expressed desire to return, stating, "I remember the prettiest street I've ever seen."

Considered the most energetic member by her groupmates, Yoon lives by the motto "If you don't walk today, you have to run tomorrow." Beyond music, she possesses a Microsoft Excel certificate, hinting at practical skills alongside her artistic talents. Currently, she shares a dorm room with Sumin, contributing to the close-knit dynamics that define STAYC's appeal among fans worldwide.

J: The Youngest with a Deep Voice

With a husky, deep tone that belies her young age, Jang Ye Eun—known professionally as J—completes the STAYC kpop lineup as the group's distinctive maknae (youngest member). Her unique vocal color and artistic sensibilities add depth to STAYC's "Teen Fresh" sound.

J's full name and age

Born Jang Ye Eun (장예은) on December 9, 2004, J currently stands as the youngest STAYC member at 20 years old (as of 2024). Hailing from Daejeon, Chungcheong, South Korea, she was officially revealed as the fifth member of STAYC through her prologue film on October 13, 2020. J was determined during her audition for High Up Entertainment, believing it might be her "last chance," consequently pouring her heart and soul into the performance that secured her spot in the group.

J's MBTI and artistic talents

J possesses an INFJ personality type, known as "The Advocate." This rare personality type is characterized by deep thoughtfulness and imagination, with advocates often leaving noticeable marks on the world through their idealistic and principled nature. Beyond singing, J demonstrates considerable artistic talent in drawing, which she lists among her hobbies alongside visiting STAYC's fancafe.

J's role as maknae and rapper

Alongside being the group's maknae, J serves as both vocalist and rapper within STAYC kpop. Hence, she balances these dual responsibilities while bringing her distinctive low-pitched voice to performances. Among her talents, she lists:

Eating a lot
Eating well
Drawing

J's unique voice and visual appeal

Perhaps J's most striking characteristic is her charismatic husky voice, which often opens STAYC songs to immediately capture listeners' attention. In the words of fans, "Songs who start with J voice are always a mega bop." Unlike her initial high-pitched singing style, J developed her signature low tone under her trainer's guidance, drawing comparisons to Dua Lipa. Especially in early STAYC songs, J handled most rap sections, though this dynamic has evolved in recent releases, with Sieun taking on more rap parts.

Visually, J cites her hair as one of her charming points, alongside her distinctive low-pitched voice. Her motto reflects her dedicated approach: "The sweat I shed will soon have a result."

STAYC Members at a Glance: Names, Ages, and Roles

For fans looking to quickly grasp key information about STAYC kpop, a comprehensive overview of the group's composition reveals fascinating patterns across their ages, positions, and personalities.

Quick reference table of STAYC members

The following table provides essential data about all six STAYC members at a glance:

STAYC members age comparison

Regarding age distribution, STAYC features a relatively balanced span without extreme age gaps between members:

Oldest members (born 2001): Sumin (March) and Sieun (August)
Middle member (born 2002): Isa
Youngest tier (born 2003-2004): Seeun, Yoon, and J

To put it differently, the age gap between oldest and youngest STAYC members is just under 4 years, creating cohesion within the group dynamic. At the time of their November 2020 debut, the members' ages ranged from Sumin at 19 to J at only 15 years old.

STAYC members positions and MBTI summary

In terms of group roles, STAYC underwent a leadership transition in 2023, shifting from Sumin's sole leadership to a co-leadership system with Sieun and Seeun. Clearly, the vocal positions are distributed strategically:

Main Vocalist: Sieun
Lead Vocalists: Isa and Yoon
Sub-Vocalists/Rappers: Sumin, Seeun, and J

Overall, STAYC's personality mix reveals an intriguing balance of introverts and extroverts: ISFJ (Sumin), ENFJ (Sieun), ESFJ (Isa), INFP (Seeun), ENFP/ENTP (Yoon), and INFJ (J). This diversity of personality types contributes to the group's dynamic chemistry, with members' MBTI types potentially explaining their natural synergy in performances and interactions.