This is a rather faithful "hot spring situation" work, where the heroine and male lead go to a hot spring together, and end up having to stay in the same room, where their relationship progresses quickly.
Your relationship with Minase the ghost changes little by little until you become lovers. And then... Live with him, though he might disappear at any time...
In the rainy season, the point when we met. It’s you, letting the dark clouds that around me dissipated and turn into sunny days. Therefore, this café is named after the sunny days that you like. It is called "Sunny Café”.