Timeslip!? Kazuto is sent to the other world one night when he is sleeping back in his own world... He wakes to find himself in the Koihime Musou universe.

The adventure continues in this alternate version of the classic Chinese historical novel "Romance of the Three Kingdoms".

Shin Koihime † Musou has all the characters from Koihime † Musou as well as new ones that make their first appearance in this game for a total of more than 50 characters.