High school student Yuna has a quiet crush on a boy she sees every morning on the commuter train. She knows only his name, Haru, and that he attends a different school. Content to admire him from a distance, she never expects her one-sided feelings to be disrupted. One morning, she wakes up to find Haru asleep in her bed, with no explanation for how he got there or why he cannot leave her room. The story follows Yuna and Haru as they navigate this bizarre situation, slowly uncovering the mystery behind his sudden appearance while their awkward cohabitation forces their feelings into the open. Their bond deepens as the initial shock gives way to shared daily life, and the inexplicable circumstances that brought them together begin to reveal a fragile, sincere connection that neither of them anticipated.