「Kyoukai no Kanata Episode 0: Shinonome」
Bundled with seventh Blu-ray/DVD volume of Kyoukai no Kanata.
Episode 0 happens two years prior to the TV series when the Nase siblings meet
Akihito for the first time in a mission for Hiroomi. Mitsuki follows her brother
on this mission and their goal is to subjugate Akihito.