Set in 1989 in Shimonoseki, Yamaguchi Prefecture, 17-year-old Tooma (Masaki Suda) lives with his father and his father's lover. Tooma witnesses his father's sadistic behavior towards his lover and, soon, Tooma finds himself following in his father's footsteps.

Toma (Masaki Suda) lives with his father, Madoka (Ken Mitsuishi), and Madoka's lover, Kotoko (Yukiko Kinoshita) on the riverside in Shimonoseki, Yamaguchi Prefecture. Toma's mother, Jinko (Yuko Tanaka), resides on the other side of the bridge, making a living by cleaning fish. Madoka routinely beats and chokes women when having a sex. As Madoka's son, Toma is afraid of becoming like his father.

On his 17th birthday in 1988, Toma has sex with his girlfriend, Chigusa (Misaki Kinoshita).

The Backwater (共喰い, Tomogui?) is a 2013 Japanese drama film directed by Shinji Aoyama, starring Masaki Suda.[1] It is based on the Akutagawa Prize-winning novel by Shinya Tanaka and adopted by Haruhiko Arai. The film won the Best Director award from the Swiss critics' federation and the Best Film award from the Junior Jury's at the 2013 Locarno International Film Festival.