Itsuki Hashima is a light novelist obsessed with little sisters, strictly focusing on them when he writes his stories. Despite his personality, he's surrounded by a tight circle of friends, including a beautiful genius writer who loves him, a big-sisterly college classmate, a fellow male writer, a sadistic tax accountant, his editor, and Chihiro, his perfect younger step-brother who takes care of the housework and cooking. As the story progresses, the underlying conflicts of dreams and goals surface, as each character attempts to achieve their dreams, in their own way.
A Sister's All You Need (Season 0)
Chihiro's All You Need (Episode 1)
Writer: Yomi Hirasaka
Air date: 2017-09-10
Runtime: 2 min
Overview: Itsuki is frustrated after his manuscript gets rejected by his editor. He hangs out at home with Chihiro (his younger “brother”), Miyako, Nayuta, and Haruto. Light banter, comedic rejection & friendship moments.
Nayuta's All You Need (Episode 2)
Writer: Yomi Hirasaka
Air date: 2017-10-09
Runtime: 2 min
Overview: Nayuta and Miyako reflect on how they met Itsuki and how their friendship developed. Some cute or comedic character build‑up.
Miyako's All You Need (Episode 3)
Writer: Yomi Hirasaka
Air date: 2017-10-23
Runtime: 2 min
Overview: Itsuki travels for inspiration with Nayuta and Miyako, then is dragged along by some other friends (like illustrator Setsuna) to places like Okinawa, Hokkaido. Small adventure vibes.
Haruto's All You Need (Episode 4)
Writer: Yomi Hirasaka
Air date: 2017-10-30
Runtime: 2 min
Overview: After work/manuscripts are submitted, the friends gather for a board game session. Itsuki reveals his feelings for Nayuta to Haruto (not knowing she heard). Ends with a reveal that one of his novels is going to be adapted into an anime.
Kaiko's All You Need (Episode 5)
Writer: Yomi Hirasaka
Air date: 2017-12-03
Runtime: 2 min
Overview: Kaiko is introduced in the regular anime series during episode 6, "Having Your Media Developments Go Well Is All You Need." In this episode, Itsuki meets the refined manga artist to discuss his work, only to discover she shares his love for little sisters.
Ashley's All You Need (Episode 6)
Writer: Yomi Hirasaka
Air date: 2017-12-10
Runtime: 2 min
Overview: The special features super-deformed, or chibi, versions of the characters in a two-minute episode.
Toki's All You Need (Episode 7)
Writer: Yomi Hirasaka
Air date: 2018-01-26
Runtime: 2 min
Overview: The anime series itself is a comedy about a novelist, Itsuki Hashima, whose life is dominated by his obsession with "little sisters". The special episode likely focuses on one of the supporting characters, Toki.
Setsuna's All You Need (Episode 8)
Writer: Yomi Hirasaka
Air date: 2018-03-23
Runtime: 2 min
Overview: The special episode focuses on the character Setsuna and is a short, 2-minute installment.
