Otoko no Isshō is a slice of life romance josei manga series written and illustrated by Keiko Nishi. It was published by Shogakukan on Flowers magazine and in four volumes compiling the chapters. A live action romantic drama film adaptation was released on February 14, 2015. It's directed by Ryūichi Hiroki and written by Hiroshi Saitō. It stars Nana Eikura and Etsushi Toyokawa.