The Kobayashi twins, Megumu and Mitsuru, were named after historical figures, but only Megumu has grown up with a taste for history. So when Mitsuru is in danger of losing his weekends to extra history classes, he convinces his sister to swap clothes with him and ace his tests! After all, how hard can it be for them to play each other?

Megumu is thinking about a career as a manga artist, but as Mitsuru so helpfully points out, her drawing skills could use a lot of improvement. That doesn't dim her enthusiasm, and she vows to practice drawing every day. But her first sketching session in a park is interrupted by an intense young man, who goes ballistic when he sees the portrait of Aoi in her sketchbook! Who is this stranger, and why does he want to destroy her boyfriend?!