The official Twitter account for the Girls und Panzer television anime series announced on Friday that every Japanese Blu-ray Disc volume of the anime will include an all-new original video anime short. Each short will be about 12 minutes long.

Bandai Visual will ship the first volume on December 21. The first edition of that volume will bundle a box for the entire series, and the anime's original character designer Humikane Shimada (Strike Witches, Sky Girls) illustrated the box.

Also bundled is a 32-page collection of Shimada's original character designs, and an advance entry form for tickets to an event on April 28, 2013. Voice actresses Mai Fuchigami (Miho Nishizumi), Ai Kayano (Saori Takebe), Mami Ozaki (Hana Isuzu), Ikumi Nakagami (Yukari Akiyama), and Yuka Iguchi (Mako Reizei), and others are scheduled to appear at the event.

The story centers around high school girls who drive tanks that exist in real life, as they compete in teams. The television series will premiere in Japan on Monday, and Crunchyroll and Anime Network will stream the anime outside Japan.

Update: There will be six volumes total, and the first volume's original video anime short is titled "Water War." The first volume will also have a 20-minute sound drama of characters' self-introductions, television commercials, the first two-minute promotional video, two audio commentaries by three staff members and three cast members, nine character playing cards and an exclusive booklet whose cover is illustrated by character designer Isao Sugimoto.