Real Name: Guk Chorok Nationality: South Korea Date of Birth: July 28, 2005 Position: Rapper, Lead Dancer Personality: Easygoing and full of energy, she leads the bright atmosphere within the team. Characteristics: She has the surname 'Guk,' which is very rare in South Korea, and is part of the group's eldest line. Trivia: She is a former contestant of the JTBC audition program "R U Next?". She expressed her bold ambition to be recognized for the group's unique identity rather than any other title.

Real Name: Shin Hyewon Nationality: South Korea Date of Birth: October 5, 2005 (Eldest line) Position: Vocalist Personality: While she is cautious and calm, she shows a surprising charm with intense immersion on stage. Characteristics: A 're-debut' member who previously promoted under the stage name 'Lael' in the child and kids-idol group 'Rich Girl.' She boasts a unique vocal color and stable singing ability. Trivia: A former Belift Lab trainee, she has an impressive history of participating in "R U Next?" alongside Jo Hyejin and Guk Chorok.

Real Name: Jo Hyejin Nationality: South Korea Date of Birth: October 24, 2007 Position: Leader, Main Dancer, Vocalist Personality: An inclusive type who looks after the members reliably like a father figure (MBTI: ENFJ). Characteristics: The final winner of the KBS audition program "The Ddanddara" and a highly skilled dancer who appeared on Mnet's "Street Dance Girls Fighter 2." Trivia: A graduate of the Practical Dance Department at Hanlim Multi Art School, she received high praise from Park Jin-young, who called her "so special."

Real Name: Undisclosed Nationality: Japan Date of Birth: August 21, 2008 Position: Vocalist, Dancer, Rapper (All-rounder) Personality: Contrary to her cute appearance, she possesses a strong grit that never gives up in any moment. Characteristics: After appearing on SBS's "Universe Ticket," she participated in KBS's "The Ddanddara" and finished in 3rd place, proving her solid skills. She is an ace who handles singing, dancing, and rapping. Trivia: She built global fandom recognition early on by going through two survival programs before her debut.

Real Name: Hsieh Chia-hsuan (謝佳軒) Nationality: Taiwan Date of Birth: February 10, 2009 Position: Main Dancer Personality: Like her name, she is baby-like and cheerful, but she has a powerful, contrasting charm on stage. Characteristics: Along with leader Jo Hyejin, she serves as a strong performance pillar for the team. She has a very high center presence in hip-hop-based stages and is characterized by her eye-catching dance lines. Trivia: She first became known as a unit member of the pre-debut single "HUNGRY (Side A)" released before the official debut.

Real Name: Achiraya Kawinwit Nationality: Thailand Date of Birth: August 18, 2009 Position: Vocalist Personality: She possesses a creative and artistic sense and prefers a free vibe. Characteristics: She is the third Thai member from JYP Entertainment, following in the footsteps of Nichkhun and BamBam. Her charming voice tone adds an exotic and trendy feel to their songs. Trivia: A former Abyss Company trainee, she has experience performing on senior artist BamBam's concert stage in Thailand before her debut.

Real Name: Undisclosed Nationality: Japan Date of Birth: December 17, 2010 (Maknae of the team) Position: Vocalist, Maknae Personality: She is adored by the older members for her maknae-like innocence and bubbly liveliness. Characteristics: She was revealed last as the team's final hidden card to complete the 7-member lineup. She is the member who best brings out the kitschy charm of OURBIRTHDAY's unique 'Whip-Hop' genre. Trivia: Despite her young age, she is considered a rising star for fancams due to her excellent facial expressions on stage.