Short specials included in the Blu-ray/DVD releases.

The story starts with Haruhiko explaining about human sense of vision, as well as optical illusions and visual preconceptions. The students of Hosea Academy goes for a summer trip by the sea. During the trip, Haruhiko states that he hates summer, and wishes that he is inside his house reading… until the other boys point […]

Each of the episodes will have the female main characters cast as Chibi Angels who hold a trial for a different character of the series. Akihito Kanbara will be the defendant for the first episode. (Source: MAL News)

The seven Blu-ray disc volumes of K-ON! have an extra short anime “Ura-ON!”