Mashiro

• Mashiro moved from Japan to South Korea to pursue her dream of becoming a K-pop idol. She spent several years training and auditioning before finally making her debut with Kep1er in 2022.

• She passed a JYP Entertainment audition held in South Korea. Mashiro reportedly placed second in the audition, an achievement that helped her enter the company's trainee program.

• She trained at JYP Entertainment from approximately 2016 to 2018. During this period, she developed her singing, dancing and Korean-language abilities.

• Mashiro trained alongside future ITZY members. Her fellow trainees included Yeji, Ryujin and Chaeryeong, with whom she developed friendships before their debut.

• She appeared in JYP Entertainment's survival program Stray Kids in 2017. Mashiro was among the female trainees featured during the competition between JYP's male and female trainee teams.

• She was associated with JYP's pre-debut female trainee team. Her participation led fans to speculate that she might eventually debut with the company's next girl group, ITZY.

• She left JYP Entertainment before ITZY debuted. Although she had trained with several future members, Mashiro did not join the group's final lineup.

• Mashiro temporarily returned to Japan after leaving JYP. During this period, she reportedly worked at a restaurant while reconsidering her future in entertainment.

• ITZY's debut motivated her to pursue another opportunity. Seeing former fellow trainees achieve their dreams reportedly encouraged Mashiro to return to South Korea and continue trying to become an idol.

• She later trained under Pledis Entertainment. This period formed another chapter in her lengthy pre-debut career before she eventually joined 143 Entertainment.

• Mashiro entered Girls Planet 999 as a trainee under 143 Entertainment. The company would later manage her activities with MADEIN.

• She received the J02 ranking during the initial Girls Planet 999 evaluations. This placed her second among the Japanese contestants at the beginning of the competition.

• Her Girls Planet 999 introduction described her as a charming marshmallow from overseas. The playful phrase became one of the memorable details associated with her contestant profile.

• Mashiro performed (G)I-DLE's DUMDi DUMDi during her introductory evaluation. The stage allowed her to demonstrate her experience as a trained idol performer.

• She participated in IZ*ONE's FIESTA performance. The demanding choreography required strong teamwork and synchronized movements.

• Mashiro led the team that performed ITZY's In the Morning. The song was especially meaningful because ITZY included several performers she had trained alongside at JYP Entertainment.

• Her In the Morning team won its Combination Mission category. The performance demonstrated her ability to guide a team while contributing her own vocals and dancing.

• She participated in the original-song performance U+Me=LOVE. Her team, 7 LOVE Minutes, won the Creation Mission benefit.

• Mashiro's teams were known for strong competition results. Her successful group performances helped establish her reputation as a reliable leader on Girls Planet 999.

• She formed a Girls Planet 999 cell with Kang Yeseo and Huang Xingqiao. Mashiro and Yeseo later debuted together in both Kep1er and MADEIN.

• She finished eighth in the Girls Planet 999 finale. Her final score of 708,149 points secured her a position in Kep1er.

• Mashiro became Kep1er's co-leader. She shared leadership responsibilities with Choi Yujin, helping support the group's multinational lineup.

• She is fluent in Japanese and Korean. Her years living and training in South Korea helped her develop the language skills needed to communicate comfortably in both countries.

• Mashiro enjoys spending time with cats. Playing with cats was one of the hobbies listed in her official Girls Planet 999 contestant profile.

• Walking is another of her favorite activities. She included walking among her hobbies during the survival competition.

• She considers cooking one of her specialties. Her Girls Planet 999 profile listed cooking alongside dancing and an amusing talent for staying still without thinking about anything.

• She is an only child. Unlike several other Kep1er members who have siblings, Mashiro grew up without brothers or sisters.

• Mashiro departed Kep1er alongside Yeseo in July 2024. The two members completed the original project contract while seven others continued promoting with Kep1er.

• She debuted in MADEIN in September 2024. The group brought together former Kep1er members Mashiro and Yeseo with other artists under 143 Entertainment.

• Mashiro released her first solo EP, 24/11, on August 19, 2026. The project marked a new milestone in her career after debuting with two different K-pop groups.