Baka & Test: Summon the Beasts

Baka & Test - Summon the Beasts - is a light novel series that received an anime adaptation which aired for two seasons from 2010 to 2011.

The story is set at Fumizuki Academy, a school where the students are divided into classes based on their results in the entrance exam. Ranging from Class A to Class F, students can also summon "Avatars", small versions of themselves that battle using special powers in Summoner Test Wars. Akihisa Yoshii is the titular Baka (Idiot) who is frustrated by the school's decision to place his childhood friend Mizuki in Class F just because she could not finish her exam due to a fever despite her intelligence, and after speaking to class representative Yuji who feels the same way as he does, the class vows to prove to everyone that there is more to life than test scores. Taking part in Summoner Test Wars, they aim to take down Class A and take their classroom for themselves.

Episode 1
Hideyoshi transforms.

Episode 2
Akihisa imagines himself undressed.

Episode 3
Akihisa's shirt flies up as he scratches his back.

Episode 5
Kouta's, Hideyoshi's, Yuji's and Akihisa's shirts fly up, Toshimitsu feels trapped, two students are changing their clothes when the door is opened, and both Yuji's and Hideoyoshi's clothes are damaged after their bracelets explode.