Yuuta Asamura has lived alone with his father for years, so when his dad suddenly remarries, Yuuta finds himself sharing a home with his new stepsister: Saki Ayase, a striking, standoffish classmate he already recognized from school. Neither of them knows how to act around the other at first, trading careful silence for cautious small talk as they work out the rules of living under one roof. This manga adapts Ghost Mikawa's original light novel.