The official website of the Oniichan wa Oshimai! (Onimai: I'm Now Your Sister!) television anime revealed additional cast, staff, key visual (pictured), and the second promotional video on Monday. The anime series adapting Nekotoufu's comedy slice of life manga premieres on January 5 at 11:30 p.m. on AT-X, followed by Tokyo MX and BS11.
Kana Yuuki (Black Clover) and Natsumi Hioka (Mitsuboshi Colors) are joining the cast as Asahi Ouka and Miyo Murosaki, respectively.
Cosplayer Enako feat. P-maru-sama. performs the opening theme "Iden Tei Tei Meltdown," which is previewed in the promotional video below. Onimai Sisters, which is composed of Marika Kouno, Kaori Ishihara, Hisako Kanemoto, and Minami Tsuda, is performing the ending theme "Himegoto * Crisisters."
Nekotoufu originally posted the manga as a doujin, also known by its short title Onimai, on Pixiv in February 2017 before Ichijinsha picked it up for physical publication in June 2018. Monthly Comic REX began serializing the manga in April 2019. The sixth volume went on sale on April 27.
Kodansha USA licensed the manga in English for digital release last June and published the fifth volume on March 22.