Ōmori was born in Tokyo as the eldest son of Akaji Maro, an actor and butoh dancer.
His younger brother, Nao Ōmori, is an actor.
[2] While in college, he began making 8 mm films, but started working as an actor after graduation.
[3] While acting in Junji Sakamoto's Scarred Angels, he also became a member of the staff.
[2] He appeared in and helped produce Hiroshi Okuhara's Wave, which won the NETPAC Award at the 2002 Rotterdam Film Festival.