Chise Takamura, a construction worker, finds herself exhausted. Her boss is noisy, the boys who work under her are selfish, and she is no longer old enough to dream about men. She is comfortable being alone and don’t want to change anything. And yet, Ichika Seo, whom she thought was just a man who was her lunch friend, confesses his love to her. Seo is gentle, hot, and really male. He gives her ardent yet enveloping love, and she doesn't know what to do with it. They are both adults, but she doesn't know what to do when she loves someone. She feels the heat in each other's bodies, it's painful and fun, like first love. The world of a woman in her 30s and a man in his 40s starts to turn around with the new "falling in love".