Junpei Takamori is a thirty-two-year-old married man and father to a young daughter named Nanaka. His career requires him to relocate to a remote work site, living apart from his wife, Azu, during the week and returning home on weekends. He finds joy in simple pleasures, such as drinking beer at home, which he considers a best moment.

He has light brown, short wavy hair, darker brown eyebrows, and light brown eyes, and is typically dressed in collared shirts, dark trousers, and dark shoes.

After his relocation, he assures his wife of his fidelity and requests the same from her. Three years later, it is revealed he had a year-long affair with a female co-worker, Rina Izutsu. Her husband, Wataru Izutsu, confronts him, resulting in Junpei returning home with visible bruises.

His wife forces him to sleep in the car and considers divorce. He expresses regret and a desire to reconcile, rediscovering his love for her and attempting to restart their life. However, he struggles to definitively reject his mistress, acting suspiciously around her and accepting favors, which fuels her obsession. He fails to clearly tell her to leave until much later.

He supports his wife’s home-based nail salon business and acknowledges the difficulties she faces managing everything alone. He looks after his daughter when needed and reassures his wife of his unchanged love.

The reconciliation is repeatedly hindered by the mistress, who employs various tactics to destroy the marriage. Despite these obstacles, he and his wife ultimately decide to remain together. The mistress’s obsession escalates to a dangerous level, including a dramatic attempt on his life, from which he survives.