The Yomota household is a modest, ordinary family: father Kinekuni, 42, mother Tamiko, 38, and their 17‑year‑old son Inumaru. One day a striking young woman named Maroko Yomota appears at their front door, claiming to be Inumaru’s granddaughter. She has traveled back in time with a time machine to visit her ancestors. Despite Tamiko’s strong objections, Kinekuni and Inumaru welcome her to stay with them, and the once‑stable family dynamic begins to unravel.