In the heart of Osaka's old neighborhoods lies a run-down apartment building known as "Copo." Its thin walls and lack of privacy are home to a group of residents, each struggling with their own pasts and uncertainties. Yuri, a part-time worker, has fled her family, while her neighbors—an aloof man who lives off women, a shy laborer with clumsy affections, and an older resident running a mysterious business—navigate their complex lives. The discovery of a fellow tenant’s death forces them all to confront their personal dilemmas and the fragile nature of life in the "Copo."
A Japan-set battle-royale comedy over a vial of sperm is centered around three women on the verge of a nervous breakdown from hearing their biological clock ticking away: a doctor and manager of a sperm bank, Sana Kobayashi, a single mother, Maron Kuribayashi, and an alluring receptionist, Mayumi Kujō. Unknowingly, the three shared a beloved partner and a sperm donor, Makoto, but lost him in a sudden accident. The night of Makoto's funeral they are shocked to discover each other in his room. In a rage of screaming, thrashing, and boasting about their own sexual prowess with Makoto, more fierce emotions erupt once Sana's plan to self-inseminate is exposed, but this leads to unexpected consequences. They affirm their real love for Makoto and reveal his true wishes.