OURBIRTHDAY Side B Members Profiles 2026: Bio, Ages & Interesting Facts
OURBIRTHDAY (아워벌스데이) is the highly anticipated new girl group under INNIT Entertainment, an independent subsidiary of JYP Entertainment. The group marks JYP’s first girl group debut since NMIXX in 2022.
OURBIRTHDAY is built around a unique concept: transforming ordinary days into moments as special as birthdays. The group was unveiled through an innovative storytelling approach, introducing members via animated characters and concept films before revealing their real faces.
The group consists of seven members split into two units:
- Side A: Cho Hyejin, Baby (Cherysha), Achiraya
- Side B: Guk Chorok, Shin Hyewon, Yu, and Kirara
This profile focuses on the four Side B members who completed the lineup in July 2026.
Quick Facts
| Category | Details |
|---|---|
| Group Name | OURBIRTHDAY (아워벌스데이) |
| Abbreviation | OBD |
| Debut Date | August 19, 2026 (scheduled) |
| Company | INNIT Entertainment (JYP Entertainment subsidiary) |
| Number of Members | 7 |
| Leader | Unconfirmed |
| Maknae | Kirara (born December 17, 2010) |
| Fandom Name | Unconfirmed |
| Official Colors | Unconfirmed |
| Genre | K-Pop |
| Nationality Mix | South Korean, Japanese |
| Current Status | Pre-debut / Active |
Table of Contents
Group History & Formation
Formation and Pre-Debut Strategy
OURBIRTHDAY represents a new approach to idol debut. Rather than revealing all members at once, INNIT Entertainment rolled out the group through a story-driven narrative involving animated characters paired with each member.
The group’s name symbolizes the aspiration to make everyday life feel as exciting and special as a birthday celebration.
Side A Introduction
On July 22, 2026, OURBIRTHDAY released their first digital single “HUNGRY (Side A)” featuring the first three members:
- Cho Hyejin (South Korea) – Winner of survival show “The Ddanddara”
- Baby / Cherysha (Taiwan)
- Achiraya (Thailand)
They performed their first stage on Mnet’s “M Countdown” on July 23, 2026.
Side B Completion
On July 25-27, 2026, the remaining four members were revealed through a second introduction film titled “NET::ERR_CONNECTION_ABORTED”. The film showed each member associated with a unique weapon:
- Guk Chorok – Gauntlet (glove weapon)
- Shin Hyewon – Hammer
- Yu – Sword
- Kirara – Bow
The Side B unit released “HUNGRY (Side B)” and began music show promotions on July 30, 2026, with an appearance on Mnet’s “M Countdown”.
Official Debut
OURBIRTHDAY is scheduled to officially debut on August 19, 2026.
Guk Chorok (국초록) Profile
Basic Information
| Category | Details |
|---|---|
| Stage Name | Guk Chorok (국초록) |
| Birth Name | Kuk Cho-rok (국초록) |
| Korean Name | 국초록 |
| Birthday | July 28, 2005 |
| Age | 21 years old ( In 2026) |
| Nationality | South Korean |
| Birthplace | South Korea |
| Position | Unconfirmed |
| MBTI | Unconfirmed |
| Height | Unconfirmed |
| Weight | Unconfirmed |
| Blood Type | Unconfirmed |
| Training Period | Unconfirmed |
Education
Guk Chorok graduated from:
- Gwacheon Elementary School (과천초등학교)
- Gwacheon Middle School (과천중학교)
- Gwacheon High School (과천고등학교)
Pre-Debut Background
- She is a former trainee who was reportedly with HYBE before joining INNIT Entertainment
- She is a South Korean trainee under INNIT Entertainment
- She was revealed as an OURBIRTHDAY member on July 25, 2026
Character Association
Guk Chorok is paired with the animated character Kiracl (키라클). Her representative weapon in the group’s storyline is a gauntlet.
Interesting Facts
- Her name “Chorok” (초록) means “green” in Korean, making her name quite unique
- She completed her entire primary and secondary education in Gwacheon, South Korea
- She is one of the oldest members in OURBIRTHDAY (born 2005)
- She was reportedly a trainee at HYBE before moving to INNIT Entertainment
- Her character wields a gauntlet, suggesting a strength-based role in the group’s lore
Shin Hyewon (신혜원) Profile
Basic Information
| Category | Details |
|---|---|
| Stage Name | Shin Hyewon (신혜원) |
| Birth Name | Shin Hyewon (신혜원) |
| Korean Name | 신혜원 |
| Birthday | October 5, 2005 |
| Age | 20 years old (In 2026) |
| Nationality | South Korean |
| Birthplace | South Korea |
| Position | Unconfirmed |
| MBTI | Unconfirmed |
| Height | Unconfirmed |
| Weight | Unconfirmed |
| Blood Type | Unconfirmed |
| Training Period | Unconfirmed |
Pre-Debut Background
Shin Hyewon is a familiar face to survival show fans. She previously appeared on:
- JTBC’s “R U Next?” – the survival show that formed HYBE’s girl group
- She was a trainee during the show
Her appearance on “R U Next?” gave her valuable pre-debut exposure and training experience.
Character Association
Shin Hyewon is paired with the animated character Kapusia (카푸시아). Her representative weapon in the group’s storyline is a hammer.
Interesting Facts
- She was a contestant on JTBC’s “R U Next?” before joining OURBIRTHDAY
- She was revealed as the first member of Side B
- She is one of the oldest members in the group alongside Guk Chorok (both born 2005)
- Her character wields a hammer, suggesting a powerful or playful image
- She expressed excitement about her debut, sharing on social media: “I can’t believe I’ve already debuted, I’m grateful every day”
Yu (유) Profile
Basic Information
| Category | Details |
|---|---|
| Stage Name | Yu (유) / U (유우) |
| Birth Name | Kawasaki Yu (川崎優) |
| Korean Name | 유우 |
| Birthday | August 21, 2008 |
| Age | 17 years old (In 2026) |
| Nationality | Japanese |
| Birthplace | Chiba, Japan |
| Nickname | Yu-chan (유짱) |
| MBTI | INFP |
| Position | Unconfirmed |
| Height | Unconfirmed |
| Weight | Unconfirmed |
| Blood Type | Unconfirmed |
| Training Period | Unconfirmed |
| Specialty | Thinking of unique ideas no one else has thought of |
Pre-Debut Background
Yu has an extensive survival show history:
| Show | Network | Year | Result |
|---|---|---|---|
| Universe Ticket | SBS | 2023 | Ranked #76 |
| THE DDANDDARA (더 딴따라) | KBS 2TV | 2024 | Ranked #3 |
| Universe Ticket (mentioned in some sources) | – | – | Contestant |
Key timeline:
- After appearing on “The Ddanddara,” she signed with INNIT Entertainment
- In February 2025, she temporarily returned to Japan for personal reasons
- In May 2025, she returned to Korea, posting a selfie on the official Ddanddara 25 SNS
- She was announced as an OURBIRTHDAY member in July 2026
Training Background
Yu trained at:
- NEXTinDANCE (NiD) Academy
- SONA Dance School
Language Skills
Yu can speak Korean and English.
Character Association
Yu is paired with the animated character Tirumiko (티루미코). Her representative weapon in the group’s storyline is a sword.
Interesting Facts
- She shares her name (in Japanese: 川崎優) with a Japanese actress of the same name
- She was the last winner from “The Ddanddara” series who hadn’t debuted elsewhere
- She has participated in three different survival shows
- Her MBTI is INFP
- She is the second youngest member of the group (born 2008)
- On stage, she is said to have a 180-degree transformation in personality
- She is known for having a persistent, never-give-up attitude
- She trained at both NEXTinDANCE Academy and SONA Dance School
Kirara (키라라) Profile
Basic Information
| Category | Details |
|---|---|
| Stage Name | Kirara (키라라) / Kilala |
| Birth Name | Takashima Kirara (たかしまきらら) |
| Korean Name | 키라라 |
| Birthday | December 17, 2010 |
| Age | 15 years old (In 2026) |
| Nationality | Japanese |
| Birthplace | Unconfirmed (Japan) |
| Position | Unconfirmed |
| MBTI | Unconfirmed |
| Height | Unconfirmed |
| Weight | Unconfirmed |
| Blood Type | Unconfirmed |
| Training Period | Unconfirmed |
Pre-Debut Background
Kirara (also romanized as Kilala) is a Japanese trainee under INNIT Entertainment. She was revealed as a member of OURBIRTHDAY on July 25, 2026.
Note: Some sources suggest she may have Filipino heritage, but this remains unconfirmed.
Character Association
Kirara is paired with the animated character Hapumi (하푸미). Her representative weapon in the group’s storyline is a bow.
Interesting Facts
- She is the youngest member (maknae) of OURBIRTHDAY, born in 2010
- She was just 15 years old at the time of the group’s pre-debut activities
- Her stage name is sometimes romanized as “Kilala”
- Her character wields a bow, suggesting an archer or ranged-attack concept in the group’s lore
- She is one of two Japanese members in the group, alongside Yu
- She is the only member born in the 2010s
Member Comparison Tables
Member Overview
| Member | Birth Name | Birthday | Age (2026) | Nationality | Weapon |
|---|---|---|---|---|---|
| Guk Chorok | Kuk Cho-rok | July 28, 2005 | 21 | South Korean | Gauntlet |
| Shin Hyewon | Shin Hyewon | October 5, 2005 | 20 | South Korean | Hammer |
| Yu | Kawasaki Yu | August 21, 2008 | 17 | Japanese | Sword |
| Kirara | Takashima Kirara | December 17, 2010 | 15 | Japanese | Bow |
Birthday & Age Table
| Member | Birthday | Zodiac | Age (2026) |
|---|---|---|---|
| Guk Chorok | July 28, 2005 | Leo | 21 |
| Shin Hyewon | October 5, 2005 | Libra | 20 |
| Yu | August 21, 2008 | Leo | 17 |
| Kirara | December 17, 2010 | Sagittarius | 15 |
Nationality Table
| Nationality | Members |
|---|---|
| South Korean | Guk Chorok, Shin Hyewon |
| Japanese | Yu, Kirara |
Survival Show Experience
| Member | Shows Participated | Network | Year |
|---|---|---|---|
| Guk Chorok | None confirmed | – | – |
| Shin Hyewon | R U Next? | JTBC | 2023 |
| Yu | Universe Ticket, The Ddanddara | SBS, KBS | 2023-2024 |
| Kirara | None confirmed | – | – |
Character Matching Table
| Member | Animated Character | Weapon |
|---|---|---|
| Guk Chorok | Kiracl (키라클) | Gauntlet |
| Shin Hyewon | Kapusia (카푸시아) | Hammer |
| Yu | Tirumiko (티루미코) | Sword |
| Kirara | Hapumi (하푸미) | Bow |
Discography
Digital Singles
| Title | Unit | Release Date | Notes |
|---|---|---|---|
| “HUNGRY (Side A)” | Side A (Cho Hyejin, Baby, Achiraya) | July 22, 2026 | Pre-debut single |
| “HUNGRY (Side B)” | Side B (Guk Chorok, Shin Hyewon, Yu, Kirara) | July 29, 2026 | Pre-debut single |
Fun Facts
- Guk Chorok’s name means “green” in Korean, making her name unique among idols
- Shin Hyewon is the only member who previously appeared on JTBC’s “R U Next?”
- Yu participated in three different survival shows before debuting
- Yu temporarily returned to Japan in February 2025 for personal reasons before rejoining INNIT
- Kirara is the youngest K-pop idol under JYP’s subsidiary to debut in 2026 at age 15
- All Side B members were revealed through a concept film titled “NET::ERR_CONNECTION_ABORTED”
- Each Side B member is associated with a unique weapon: gauntlet, hammer, sword, and bow
- Guk Chorok completed her entire education in Gwacheon, from elementary to high school
- Yu can speak Korean, Japanese, and English
- Yu’s MBTI is INFP
- Shin Hyewon expressed her gratitude about debuting on social media
- Kirara is sometimes romanized as “Kilala”
- Yu is known for having a 180-degree personality transformation on stage
- Yu is described as having a persistent, never-give-up mentality
- Guk Chorok was reportedly a former HYBE trainee
- The Side B unit began music show promotions on July 30, 2026, on M Countdown
- OURBIRTHDAY is JYP Entertainment’s first girl group since NMIXX in 2022
- Yu trained at both NEXTinDANCE Academy and SONA Dance School
- The group’s concept is to make ordinary days feel like birthdays
- Kirara shares her name with the Japanese word for “glitter” or “sparkle”
FAQs
Who are the Side B members of OURBIRTHDAY?
The Side B members are Guk Chorok, Shin Hyewon, Yu, and Kirara. They were revealed in July 2026 as the second unit of the group.
When is Guk Chorok’s birthday?
Guk Chorok was born on July 28, 2005.
When is Shin Hyewon’s birthday?
Shin Hyewon was born on October 5, 2005.
When is Yu’s birthday?
Yu (Kawasaki Yu) was born on August 21, 2008.
When is Kirara’s birthday?
Kirara was born on December 17, 2010.
What is the age difference between the oldest and youngest Side B members?
The oldest Side B member is Guk Chorok (born 2005, age 21) and the youngest is Kirara (born 2010, age 15), making a 5-year age gap.
Which survival shows did Yu participate in?
Yu participated in SBS’s “Universe Ticket” (2023) and KBS 2TV’s “THE DDANDDARA” (2024), where she ranked #3.
Did Shin Hyewon appear on any survival show?
Yes, Shin Hyewon appeared on JTBC’s “R U Next?” in 2023.
What is the debut date of OURBIRTHDAY?
OURBIRTHDAY is scheduled to officially debut on August 19, 2026.
What company manages OURBIRTHDAY?
OURBIRTHDAY is managed by INNIT Entertainment, an independent subsidiary of JYP Entertainment.
What are the weapons associated with each Side B member?
- Guk Chorok: Gauntlet
- Shin Hyewon: Hammer
- Yu: Sword
- Kirara: Bow
Conclusion
OURBIRTHDAY’s Side B members – Guk Chorok, Shin Hyewon, Yu, and Kirara – bring a diverse mix of talent, experience, and international flavor to the group. With members from South Korea and Japan, ages ranging from 15 to 21, and survival show veterans alongside fresh faces, the quartet completes a well-rounded seven-member lineup.
Guk Chorok brings stability as one of the oldest members with a unique name and rumored HYBE training background. Shin Hyewon arrives with survival show recognition from “R U Next?” and a warm, grateful personality. Yu is the seasoned survival show competitor with three programs under her belt, trilingual abilities, and an INFP personality. Kirara, the youngest maknae born in 2010, represents the fresh, youthful energy of the group.
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