After the passing of his parents, Koutarou finds himself managing their coffee shop alone. His only companion is a cat and, despite concerns from those around him about his loneliness, Koutarou struggles to forge deep connections with others. One day, a self-proclaimed angel appears before him — Rudy.

“I’ve been waiting. I want to hear you sing,” Rudy says. Koutarou’s heart skips a beat — he had abandoned music a long time ago.

Rudy decides to move in with Koutarou — not that Koutarou agreed to anything — and, from there, their life as housemates begins…