Office worker Natsuki Souta, whose fiancée cheated on him, ends up helping JK Kanzaki Airi, a high school girl whose parents skipped town and abandoned her.

When he showers this love-ignorant girl with plenty of affection, Airi grows completely attached to Souta and secretly begins to harbor romantic feelings for him.

Souta, too, comes to feel happiness in the peaceful days he spends together with kind, great-at-cooking Airi. Then one day, as he’s troubled over his mother pressuring him to “hurry up and introduce your fiancée,” Airi shyly says:

“Um… could I be your fiancée, just for one day, Souta-kun…?”

A perfectly compatible pair weave a cohabitation rom-com overflowing with nothing but happy-happy bliss!