Reitaro is an ordinary salaryman, but his household is governed by a bizarre rule set by his wife, Kazumi: he must not cross a tape dividing the hallway. Ignored by Kazumi and their daughter Ichika, Reitaro is confined to a dark, cramped room. Ichika finds the family dynamics strange and wishes to mend them, but her mother’s strictness prevents her from speaking to her father. One day, Reitaro is saved from a car accident by Sayako, who points out that his situation resembles domestic violence. This encounter strengthens Reitaro’s desire to restore his family. The question remains whether Ichika and Reitaro can unravel the mystery behind the hallway tape—representing the family's secret—and bring back days of harmony and laughter. With determination and newfound awareness, Reitaro and Ichika embark on a journey to heal their fractured family and overcome the barriers imposed by Kazumi.