To college student Mahiru, relationships are just a cycle of hellos and good-byes. She only sticks around when the going is good and doesn't want any pesty deep connections. That all changes when she gets to know her next-door neighbor Kazuhiko, a kind-hearted man who's over ten years her senior. Although she goes into this new friendship with her usual blase attitude, their relationship becomes more important than she could have ever imagined...