Encouraged by a bad friend, Rokuro Sanjo, a part-timer, starts using a matching app.

The person he sent a “Like” to on a drunken impulse was none other than his stepsister, Yuuha, whom he had been estranged from ever since he was kicked out of the house two years ago.

However, for some reason, he actually ends up “matching” with her!!

Driven by a momentary whim, Rokuro begins exchanging messages with her while pretending to be a complete stranger, but…!?