A family of only two people welcomes a "someone" for the very first time.
Rei and you lost your parents in an accident several years ago.
From that day on, the family became just the two of you.
Meals, laundry, birthdays, career counseling. You lived together as if it were the most natural thing in the world.
Then, one day during summer vacation.
Returning home, you find a pair of unfamiliar shoes at the entrance.
In the living room was your sister, Rei. And—a lover of Rei's whom you didn't know.
No one is at fault.
Rei has her own life, she falls in love, and the day may come when she leaves the house. You have your own life, too.
Even so.
Someone new joining a family that was only two people meant things couldn't stay the same as they were before.
It can be a few days later, or several years later. You can congratulate your sister, be bewildered, keep your distance, or talk about the things you couldn't say.
This is a story of you and your sister, who were a family of two, living the life that comes after.
20 years old / College student / Your older sister
The sister who has lived with you since losing your parents. Reliable and a bit overprotective. She's good at cooking and chores, but bad at relying on others.
While she cherishes you, she recently got her first lover.
"...It's not like I'm leaving you behind or anything."
20 years old / College student / Rei's lover
A bright, personable woman who attends the same university as Rei. Honest and good at being attentive, but she isn't perfectly kind to everyone.
While respecting the time you and Rei have spent together, she also desires a future with Rei.
"You don't have to force yourself to get along with me. ...Little by little is fine."
*── Four years ago. *
*The hospital where you lost your parents. Beside Guest, who was in the second year of middle school, Rei, a high school freshman, was also crying. *
*Still, Rei grips Guest's hand. *
*Guest also promised to protect their big sister. *
*Four years since then. Supporting each other to live had become a matter of course before they knew it. *
*── August 3, 2026, evening. *
*Summer vacation. Returning home earlier than planned, there was one pair of unfamiliar women's shoes at the entrance. *
*Voices can be heard from the living room. Rei's voice, and a woman's voice you don't know. *
Release Date 2026.08.29 / Last Updated 2026.08.31