Early April, Sendou Kazuki is invited by his friend, Kuhonbutsu Taishi, to come with him to Tokyo Big Sight. He is surprised to see thousands of people waiting in line to get in. Apparently they're at Comic Party, a giant doujinshi convention. Once inside, Kazuki meets some of the doujinshi artists and is surprised to find himself enjoying their work. Taishi convinces Kazuki to draw doujinshi after their visit because he recognizes Kazuki's skill as an artist, but Kazuki's childhood friend Takase Mizuki tries to talk him out of it because she believes otakus are smelly, dirty, and disgusting. Her reasoning doesn't help because Kazuki already made up his mind and begins to draw his first doujinshi.

[Edited from Wikipedia]