Pants no Mikiri

The main character, Reimu Hakurei, complains to Marisa Kirisame, "When I went to change my pants for the first time in two weeks, my pants were gone."

Marisa did not lend me her pants.
So Reimu decides to rob every pair of pants she meets from now on.

Résumé

This game is an arrangement of a certain famous mini-game with characters from Touhou Project.