Riho Sayashi

Riho Sayashi trained at Actors School Hiroshima from 2005 to 2010, and in 2010 she passed the JC and JK actress audition and appeared in the stage play Fashionable in June of that year. On January 2, 2011, she was introduced as part of the ninth generation of Morning Musume, alongside Ikuta Erina, Suzuki Kanon and Fukumura Mizuki, and the group made its debut at the Hello! Project winter concert that day. She went on to become the only ninth generation member to receive solo lines in a 2011 release.

While in the group she also built an acting record. She appeared in the film Share House in 2012 and played Nagata Sana in the Nippon TV drama Suugaku Joshi Gakuen the same year. Her stage work included Momo in Stacies: Shojo Saisatsu Kageki in June 2012, Lily in the musical Lilium: Shojo Junketsu Kageki in June 2014 and Kiri in Triangle in June 2015. She graduated from Morning Musume on December 31, 2015.

The next stage of her career took her away from Japan. From 2016 she spent about two years in New York and other places abroad, studying dance and English, and in December 2018 she left Hello! Project. She returned to the stage on March 30, 2019, at the Hello! Project Hinafest, and from June 2019 to February 2020 she toured with BABYMETAL as a support dancer, performing at festivals and venues in Japan, Europe and the United States including the Glastonbury Festival in 2019.

After joining Japan Music Entertainment in September 2020, she returned to the stage as Lily in Kuro Sekai and as Sarah in the musical 35MM: A Musical Exhibition, and she appeared in guest roles on television in 2021, including Katsuragi Nanako in the Fuji TV series Junkyoju Takatsuki Akira no Suisatsu, Yamana Shori in Anonymous on TV Tokyo, Haruka in Chef wa Meitantei, and Yuka in the NHK series Shukatsusei Nikki. In 2022 she played Moriyasu Rioko in Ore no Kawaii wa Mosugu Shohi Kigen on TV Asahi, and in 2023 she played Kiuchi Shizue, a shy office worker, in the NHK series Watashitte Sabasaba Shiteru Kara.

Her first leading roles followed. In 2023 she played the title lead Mendo Tsuyu in the first season of Mentsuyu Hitori Meshi, and she returned to the part in Season 2 in 2024. Also in 2024 she led the TV Tokyo drama Oshi wo Meshiagare as Tomota Toshiko, an enthusiast who joins a company’s publicity team, and she appeared as Natsu in the film Juichinin no Zokugun. In 2025 she played Okuda Sanae in Oboe no Nai Satsujin on NHK BS, Yoshioka Asuka in the TBS drama Madoka 26 Sai Kenshui Yatteimasu, and Misa Amane in Death Note: The Musical.

Her 2026 role is Sawatari Saeko in the girls love drama How Do We Relationship?, known in Japan as Tsukiatte Agete mo Ii ka na, opposite Sakurako Konishi as Inuzuka Miwa. The eight episodes began on MBS on Thursday, September 10, 2026, in the 24:59 slot, with regional stations including TV Kanagawa, Chiba TV, Tele Tama, Tochigi TV and Gunma TV also scheduled, and global streaming on GagaOOLala outside Japan and Korea. It was directed by Yamada Kana and Hong Sun Hye from a script by Matsugasako Miki.

One comparison stands out. In Mentsuyu Hitori Meshi she plays a laid-back office worker in a series built around solo meals, and Kiuchi Shizue in Watashitte Sabasaba Shiteru Kara is a timid colleague overshadowed by the lead. Saeko is the reverse, a bright, free spirited woman with dyed blonde hair who is open about what she wants, and every scene she plays is defined by her relationship with one other person. The shift from solitary and reserved characters to a partner defined by dialogue shows how far her range has moved from the dance stage where she began.