, is a Japanese singer and actor. He debuted as a member of the Japanese boy band JO1 in 2020, after placing first in the first season of Produce 101 Japan. He made his debut as an actor in 2021 and played Kamen Rider Chimera in the Kamen Rider Revice films.
Early life and education Issei Mamehara was born on May 30, 2002, in Maniwa, Okayama, Japan. During his early years, he developed a passion for physical activities, participating in baseball, swimming, and sumo tournaments throughout his school life. Mamehara's interest in dance emerged during elementary school, inspired by his older sister's dance classes. This interest deepened when he became a fan of the boy band Generations from Exile Tribe after watching one of their televised performances, prompting him to enroll in a dance school in his second year of junior high. He specialized in 1990s hip hop dance and began teaching children at the same dance school by his freshman year of high school. Mamehara also grew up with a deep appreciation for tokusatsu media, particularly the Kamen Rider franchise, and aspired to appear in the series as an actor.
Mamehara graduated from high school in March 2021.
Career 2019–2020: Produce 101 Japan and debut with JO1 After failing a series of auditions in 2019, Mamehara's older sister, a fan of South Korean Produce 101, suggested he try out for Produce 101 Japan. Having limited knowledge about K-pop, he initially refused to apply because he wanted to be a professional dancer instead. He eventually applied a day before the deadline, following his sister's encouragement. The show was held from September to December, where he finished first with 261,583 votes.
Following an "intense" boot camp in South Korea, seventeen-year-old Mamehara debuted as a member of the resulting boy group JO1 on March 4, 2020, with the release of their first single Protostar under Lapone Entertainment. His win awarded him the choreographic center position in the group's debut song, "Infinity".
2020–present: Acting debut In November 2020, Mamehara was named Mezamashi TVs monthly entertainment presenter, making him the segment's youngest presenter at that time. He then took acting classes and made his acting debut in the Yoshimoto Kogyo-produced anthology film, Meters Away, Worlds Apart in 2021, alongside Produce 101 Japan host and comedian Takashi Okamura. In 2022, Mamehara was cast as Kamen Rider Chimera in the film . He reprised his role in Birth of Chimera (2022), an exclusive Toei Tokusatsu Fan Club spin-off film that delves into his character's backstory.
In 2023, he made his small screen debut in NHK's , as the humanoid Hiroshi. In the following year, he made his TBS Sunday Theatre debut in the Ryunosuke Kamiki-led drama . In February 2025, Mamehara was appointed as an ambassador to his hometown of Maniwa. Later that year, he played the lead role of Tsukasa Kiriki for the live action movie adaptation of the manga Bad Boys and co-starred opposite in the family drama Mt. Fuji, Coffee, and the Formula for Happiness. He played Ichige's grandson, Takuma, a university student who likes coffee and discovers his dream with his grandmother. In July 2026, Mamehara co-starred alongside Rino Katase on the TV Tokyo's drama Fūfu to 16-sai: Kyōki no Rinjin (). He played Hiro Nomura, the married man Katase's character falls in love with, and sang the theme song "Murasakiiro" (), written by his bandmate Takumi Kawanishi.
Discography
Singles + Title Year Peak chart positionSales Album JPNDLPeaks on the Billboard Japan Download Songs chart: "Not Puppy Love": "Murasakiiro": "Not Puppy Love" 2025 47 JPN: 715 rowspan=2 "Murasakiiro" () 2026 32 JPN: 759
Songwriting credits All song credits are adapted from the Japanese Society for Rights of Authors, Composers and Publishers's database, unless otherwise noted. When searching, put "MAME" under 著作者名 (Author's name) and "LAPONEエンタテインメント" under 出版者名 (Publisher's name). +Key Indicates a non-commercial release
+ Title Year Artist(s) Album Lyrics Credit With "Breaking the Rules" 2023 Keigo, Takumi, Máme 2023 JO1 2nd Arena Live Tour "Beyond the Dark – Rise in Kyocera Dome" Keigo, T.K, Máme "Not Puppy Love" 2025 Máme rowspan=2 Sean Bowe "Mama" () Makka
Filmography
Film + Year Title Role Note 2021 Meters Away, Worlds Apart Hiroki Asada Segment: "Today is A Good Day" 2022 Nozomu Otani / Kamen Rider Chimera 2025 Bad Boys: The Movie Tsukasa Kiriki Lead role Mt. Fuji, Coffee, and the Formula for Happiness Takuma Andō Lead role
Television + Year Title Role Note 2019 Produce 101 Japan Contestant Finished 1st 2020 Mezamashi TV Host of the month For November 2020 2022 Short Program Hajime Toshino Lead role; anthology series Kamen Rider Revice Movie Spin-Off Web Drama: Birth of Chimera Nozomu Otani Lead role; television film 2023 Hiroshi Tanaka Azatoi Type A to Z Takuma Drama segment of Nobuyuki Yamamoto 2024 Mame's and Sho's Best Holiday - JO1derful Tour Himself With Sho Yonashiro Seiya 2026 Hiro Nomura Lead role
Music videos + Title Year Director "Not Puppy Love" 2025 Fumiya Hirai "Mama" () Shun Murakami (Vil Tokyo)
Footnotes
References
External links Official website