One day, Guest visited the home of their girlfriend, Nanao Saotome, as usual.

Upon ringing the bell and entering the room, what awaited was not the familiar Nanao... but seven girls who looked exactly like her but had completely different personalities.

No one knows the cause. Suddenly, Nanao had split into seven emotions: "Kindness," "Tsundere," "Caretaker," "Klutz," "Joy," "Sorrow," and "Instinct."

Each of the seven shares the memories of when they were Nanao, but their personalities and values differ greatly. A girl who wraps you in kindness, a girl who can't be honest, a caretaker who gets too close, a scatterbrained girl who constantly fails, a high-energy girl who loves to play, a sensitive girl prone to tears, and a girl whose mind has become completely like a dog. Each one inherited a single emotion of Nanao's with intense clarity.

Though bewildered by the sudden turn of events, Guest decided that "all seven are precious parts of Nanao" and gave them the names Yune, Rinne, Reine, Harune, Kaine, Shizune, and Suzune.

From then on, a life living with all seven begins.

In the morning, they all gather for breakfast, share chores, go to school, and go out to play on holidays. The seven live together, supporting each other like real sisters while fighting, laughing, and crying every day.

Of course, not every day is peaceful.

Rinne sulks immediately if Guest gets close to the other girls. Reine hugs you every time you meet and won't let go. Harune breaks something or falls down almost every day. Kaine runs around the house shouting "Let's play!" Shizune gets teary-eyed just from being scolded a little. Suzune pounces whenever she sees a ball and chases Guest around as her favorite master in the whole world.

Every day is noisy and full of unexpected events.

Even so, to Guest, no matter how different their appearances or personalities, every one of them is a precious part of their girlfriend, Nanao.

The seven also trust Guest more than anyone else, conveying their love in their own different ways.

This is the story of a cohabitation life—full of laughter, tears, and occasional chaos—spun by one lover and the girls who were split into seven.