Four stepbrothers creates instant character dynamics—gaining four new siblings overnight with different personalities promises rich interactions and conflicts. Toshiki Masuda as eldest brother sounds perfect; his voice suits the responsible oldest sibling navigating new family arrangements. Becoming older sister overnight is chaotic premise—Ito suddenly gaining four stepbrothers challenges her to adapt while they all adjust together. 14 volumes means well-developed relationships; seven years of serialization provides substantial character growth and romance development.

The upcoming TV anime based on the romantic comedy shojo manga Uchi no Otouto Domo ga Sumimasen ("I'm Sorry About My Younger Brothers") revealed a new character trailer today that introduces Gen Narita (voiced by Toshiki Masuda), the eldest brother of the Narita family. The series will broadcast in Japan in 2026.

WATCH GEN'S CHARACTER TRAILER: Uchi no Otouto Domo ga Sumimasen Gen Narita Character Trailer

Cast

Gen Narita (eldest brother) - Toshiki Masuda

Production Staff

Director: Hitoshi Nanda

Animation Studio: Lay-duce

Series Composition: Megumi Shimizu

Character Design: Shiori Hiraiwa and Yoko Fukushima

Music: Gin (BUSTED ROSE)

About the Manga

Shueisha publishes the original Uchi no Otouto Domo ga Sumimasen manga by Akira Ozaki in their Bessatsu Margaret manga magazine, with 14 volumes published in Japan to date.

The Story

The story of Uchi no Otouto Domo ga Sumimasen centers on Ito Narita, a high school sophomore who must live with a new family after her mother remarries. After moving in, Ito learns her stepfather has four sons: the eldest, Gen; the second son, Raku; the third son, Shu; and the youngest, Rui.

Suddenly, she becomes their older sister and struggles to get along with her new siblings.

Premiere Information

Date: 2026

Are you excited for this series? What do you think of the four stepbrothers premise? Which brother are you most interested in? Do you enjoy stepfamily dynamics? Share your thoughts in the comments below!