An opening theme performed by the fictional band 'Tenchu Girls' in the series and was included in the 4th volume of the Blu-ray/DVD releases.
Originally, Tenchu Girls is the magical girl TV anime that appears in Episode 2 of the show, but because of their popularity, an idol unit of the same name set to release their debut single "Mirai Girl" on July 2, 2014. The seven members of the unit were: Saki Fukasawa (Tenchu Red), Rika Sasaki (Tenchu Pink), Megumi Nishikiori (Tenchu Yellow), Saori Itayama (Tenchu Blue), Kurumi Watanabe (Tenchu Green), Akina Sawada (Tenchu Purple), and Erika Kaiho (Tenchu Black). Fukasawa, Nishikiori, and Itayama are also currently the members of Japanese idol group Rabuken, the 4th generation trainees of Lovely Doll. Before the release, they made their live event debut in the "Black Bullet Special Event Early Summer Festival" held at Akihabara UDX on May 25, 2014.
Короткий специальный эпизод с участием 'Девушек Тенчю', группы персонажей из телесериала. Включён в 4-й том релиза Blu-rayDVD.
