Meet Chako and her friends from the Cosplay Association at East Oizuki Academy! They're the hottest new cosplay team in Japan...fresh from a winning streak of local battles, they're set to sweep the Cosplay World Series! Yeah, right. In reality, Chako and her friends are barely able to keep their club alive at all. Feeble club membership and a lack of sponsorship might be the end of their cosplay dreams before they can even start. But don't you dare underestimate this group of spunky girls! They'll survive a barrage of pervy newcomers, cosplay rivalries, costume disasters and dating mishaps in order to reach their ultimate goal of competing in the World Series. The clothing flies as the girls suit up (and strip down) for Cosplay Complex!

The story centers on Nayu, a middle school girl who shocks her schoolmates on the first day of school by wearing black lace panties. She likes this kind of underwear, and she tries to "spread the word on the merits of [these kinds of] underwear" via an underwear club with her schoolmates, who are worried about their bodies' development and which underwear to choose.

An OVA summarizing all 25 episodes of season 1 from Lelouch's viewpoint.

Many people have fond memories of meeting a certain teenage boy in their younger years. However, their ages vary widely, and each remembers him as a teen. This story follows the intricate intertwining of their various stories and how this young man, who apparently lives outside of time, has affected each of them.