My Friend's Little Sister Has It In for Me! (友達の妹が俺にだけウザい, Tomodachi no Imōto ga Ore ni Dake Uzai), or ImoUza!, is a Japanese light novel series written by Ghost Mikawa and illustrated by Tomari. The series began publication by SB Creative under their GA Bunko imprint in April 2019. The light novel is licensed in North America by J-Novel Club. A manga adaptation by Hira Hiraoka began serialization online in December 2019. An anime television series adaptation produced by Blade aired from October to December 2025.
Contents
Plot
The series follows Akiteru Ōboshi, an ordinary student who is best friends with his classmate Ozuma Kohinata. Iroha, Ozuma's younger sister, often hangs out at his house and acts annoying towards him, a contrast to her in-school persona as a kind and diligent honor student. One day, he is asked by his uncle to start a relationship with his cousin Mashiro Tsukinomori in exchange for him providing support for his game development group, which they call the 5th Floor Alliance. Meanwhile, Iroha aims to be a professional voice actress, providing the voices for the 5th Floor Alliance's work, but does so in secret due to her family's disapproval of her interests.
Characters
Main characters
Akiteru Ooboshi (大星 明照, Ooboshi Akiteru)
Voiced by: Haruki Ishiya
Akiteru is a second year high school student. In the series, Akiteru calls himself a well-rounded average student but still has a hidden side to him.
Iroha Kohinata (小日向 彩羽, Kohinata Iroha)
Voiced by: Sayumi Suzushiro
Iroha is Akiteru's best friend's younger sister. In the story, Iroha is a bright, kind, and beautiful honor student. She is described as an excitable person who also acts clingy towards Akiteru. She aims to become a voice actress. When she was in junior high school, she was on bad terms with Ozuma and was a loner, with only her dream of becoming a voice actress pushing her forward, despite her mother's disapproval. However, after meeting Akiteru, she opens up and gets into voice acting.
Mashiro Tsukinomori (月ノ森 真白, Tsukinomori Mashiro)
Voiced by: Tomori Kusunoki
Mashiro is a second year high school student, classmate and cousin of Akiteru. She is childhood friends with Akiteru and often played with him when they were younger. In the story, Mashiro is described as a gentle person when meeting strangers with a cold demeanor towards Akiteru. She speaks in the third-person. She is also a popular novelist who writes under the pen name Namako Makigai (巻貝 なまこ, Makigai Namako).
Ozuma Kohinata (小日向 乙馬, Kohinata Ozuma)
Voiced by: Soma Saito
Ozuma is a second year high school student and Iroha's older brother. In the story, Ozuma is a kind and caring person. He is described as "handsome like a prince" and is a genius programmer. Ozuma is Akiteru's only friend and has absolute faith in Akiteru due to some past events.
Supporting characters
Makoto Tsukinomori (月ノ森 真琴, Tsukinomori Makoto)
Voiced by: Katsuyuki Konishi
Mashiro's father and Akiteru's uncle. He is the president of the large entertainment enterprise Honeyplace Works.
Otoha Kohinata (小日向 乙羽, Kohinata Otoha)
Voiced by: Atsuko Tanaka (drama CD)
Otoha is the mother of both Ozuma and Iroha.
Kou Kageishi (影石 鉱, Kageishi Kou)
Sumire and Midori's Grandfather.
Mizuki Tsukinomori (月ノ森 海月, Tsukinomori Mizuki)
Mashiro's mother.
Asagi Tachibana (橘 浅黄, Tachibana Asagi)
Voiced by: Sayaka Kikuchi
Media
Light novels
The light novel series is written by Ghost Mikawa and features illustrations by Tomari. It is published by SB Creative under their GA Bunko imprint, with the first volume being released on April 15, 2019; eleven volumes have been released as of March 2025. The series is licensed in English by J-Novel Club.
Manga
A manga adaptation by Hira Hiraoka began serialization in Square Enix's Manga Up! online web service on December 13, 2019, and has been compiled into eleven tankōbon volumes as of May 2026. The manga is set to end with the release of its twelfth volume. The manga is published in English in North America by Comikey and Square Enix through the global version of Manga Up!.
Anime
An anime television series adaptation was announced during a livestream for the "GA Fes 2021" event on January 31, 2021, with the cast of the series' drama CDs reprising their roles. It is produced by Blade and directed by Kazuomi Koga, with series composition and screenplays by Touko Machida, character designs Katsuyuki Sato, and music by Tsugumi Tanaka, Kaho Sawada, Kanade Sakuma and Hanae Nakamura. The series aired from October 5 to December 21, 2025, on the NUMAnimation programming block on TV Asahi and its affiliates. The opening theme song is "Uza Kawaikute Nani ga Warui!" (ウザ可愛くて何が悪い！; 'What's Wrong With Being Annoyingly Cute!'), performed by Karubi Akami, while the ending theme song is "Hoshi no Kodō" (星の鼓動; 'Beat of the Star'), performed by Kohana Lam. Crunchyroll streamed the series.