Ren’ai 0 Kilometer

A mother with five daughters and a father with four sons decide, as reckless parents do, to swap one kid between households for three months. Kyouichi ends up on loan, treated like a real onii-chan by his new sisters, while the girl who got traded out to make room for him is stuck watching from outside and quietly furious about it.

The setup is temporary by design, which is exactly the problem: three months isn't long enough for anyone's feelings to sort themselves out cleanly, least of all Kyouichi's, caught between belonging somewhere new and being missed by someone he left behind.

Play unfolds as a visual novel dating sim built around that swap, with Kyouichi's choices steering how close he gets to which sister, whether the jealous girl gets pulled back into the picture, and which of several endings the pretend-family arrangement ends up landing on. Voiced dialogue and a school backdrop keep the everyday scenes grounded even as the family situation gets increasingly less pretend.