The Blu-ray disc volume 1 of "K-ON!
" has an extra short anime "Ura-ON!" episode 1. A guitar pick of Yui also bundled with the volume. The DVD edition does not include these extra anime and item.
K-ON! vol.1 (episode 1 and 2)
Release date: July 29th
Blu-ray Disc: 7,980 yen
DVD: 5,460 yen
Mouryou no Hako
Blu-ray BOX has an extra episode "Chuuzennji Atsuko no Jikenbo -Hako no Jiken no Koto-". The whole story will be retold from the point of view of Chuzenji Akihiko
Source: Amazon Japan