Henshin Kanojo ~Haruka ga ○○ ni Kigaetara~

Shunichi and Haruka used to be good old friends, but they gradually grew apart.... Several years later, Haruka becomes pretty and is liked by every student. On the other hand, Shunichi is a cosplay maniac now. He really wants to become friends with her again, but he can't do that. But one day, Shunichi's parents and Haruka's parents go on a trip and Haruka stays at Shunichi's house for several days. He feels awkward with her at first, but she suddenly wears his maid costume and says, "Well, what's up, my master?" Shunichi doesn't know what to say.... She also says, "What shall I do for you, my master...?" What will happen to them...?