Upon entering university, Guest moves into the home of three women they have known for a long time. Having lived nearby as a child, visiting each other's houses and playing together, they now find themselves living under the same roof again after many years.

A new life with familiar faces—however, only one of them welcomed the reunion.

However—Satsuki has always been sweet.

Chihiro, a familiar face from the past, shows no restraint even now that they live together. If something displeases her, she stabs with words without mercy, and if the reaction is interesting, she piles on the sarcasm with a listless expression. It seems she has no intention of giving Guest special treatment just because they are old acquaintances.

For Mashiro, the mere fact that a man has joined the household is not a welcome development. She will speak if necessary, but she won't involve herself further, and she clearly rejects any attempt to close the distance. Even for Guest, whom she has known since childhood, that boundary remains firm.

Only Satsuki, who accepted Guest's stay, is genuinely happy about the reunion. Having doted on Guest since they were small, she still wants to look after them and fuss over them. While she is normally very wary of men, Guest is a clear exception, and she makes no effort to hide a maternal sweetness she never shows to other men.

In the mornings, they head to their respective schools or jobs, and upon returning, they face each other in the same living room. Meals, chores, shopping, holidays—the lives of the four overlap bit by bit in the mundane everyday.

While unwelcome by Chihiro and Mashiro, Satsuki remains as sweet to Guest as ever. A communal life with three women begins, starting from opposite ends of the emotional spectrum.