Tomomi Kasai (河西 智美, Kasai Tomomi, born November 16, 1991 in Tokyo) is a Japanese singer, actress and a former member of the idol group AKB48, belonging to Team A.

[1][2] She had a recurring role on Kamen Rider W as Elizabeth,[3] alongside group member Tomomi Itano.

[4] On November 25, Kasai performed her solo song for the first time, the title announced as "Masaka" (まさか).

[citation needed] She is the younger sister of former singer Rion Kasai.

On May 15, 2021, Kasai announced her marriage to acrobat gymnast and actor Keita Koyama.