My Friend's Little Sister Has It In for Me!

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 is set to premiere in October 2025.

My Friend's Little Sister Has It In for Me!
First light novel volume cover featuring Iroha Kohinata
友達の妹が俺にだけウザい (Tomodachi no Imōto ga Ore ni Dake Uzai)
Genre	Romantic comedy[1]
Light novel
Written by	Ghost Mikawa
Illustrated by	Tomari
Published by	SB Creative
English publisher	NA: J-Novel Club
Imprint	GA Bunko
Original run	April 15, 2019 – present
Volumes	11
Manga
Written by	Ghost Mikawa
Illustrated by	Hira Hiraoka
Published by	Square Enix
English publisher	NA: Comikey Square Enix
Magazine	Manga Up!
Original run	December 13, 2019 – present
Volumes	9
Anime television series
Directed by	Kazuomi Koga
Written by	Touko Machida
Music by	Tsugumi Tanaka Kaho Sawada Kanade Sakuma Hanae Nakamura
Studio	Blade
Original network	ANN (TV Asahi), BS11
Original run	October 2025 – scheduled

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 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 Ōboshi (大星 明照, Ōboshi Akiteru)

Voiced by: Haruki Ishiya^[2]

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^[2]

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.

Mashiro Tsukinomori (月ノ森 真白, Tsukinomori Mashiro)

Voiced by: Tomori Kusunoki^[2]

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^[2]

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.

Sumire Kageishi (影石 菫, Kageishi Sumire)

Voiced by: Kana Hanazawa^[2]

Sumire is Akiteru's subject teacher. She is described as a ruthless guidance and has a poisonous tongue. She secretly works as an illustrator under the pen name Shikibu Murasaki (紫 式部, Murasaki Shikibu)

Midori Kageishi (影石 翠, Kageishi Midori)

Voiced by: Reina Kondō^[3]

Midori is Sumire's little sister and the President of the Drama Club.

Otoi (音井, Otoi)

Otoi is a second year high school student. She is a sound engineer.

Kanaria Kiraboshi (綺羅星 金糸雀, Kiraboshi Kanaria)

An idol and a famous editor at UZA Publishing.

Sasara Tomosaka (友坂 笹, Tomosaka Sasara)

A first year high school student. She is an influencer on Pinstagram.

Supporting characters

Makoto Tsukinomori (月ノ森 真琴, Tsukinomori Makoto)

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)

Otowa is the mother of both Ozuma and Iroha.

Kou Kageishi (影石 鉱, Kageishi Kou)

Sumire and Midori's Grandfather.

Kaigetsu Tsukinomori (月ノ森 海月, Tsukinomori Kaigetsu)

Mashiro's mother.

Asagi Tachibana (橘 浅黄, Tachibana Asagi)

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.^[4] The series is licensed in English by J-Novel Club.^[5]

No.	Original release date	Original ISBN	English release date	English ISBN
1	April 12, 2019[6]	978-4-8156-0187-4	February 10, 2021 (digital)[7] December 7, 2021 (print)[8]	978-1-71-832680-4
2	July 12, 2019[9]	978-4-8156-0277-2	April 23, 2021 (digital)[10] February 1, 2022 (print)[11]	978-1-71-832681-1
3	November 14, 2019[12]	978-4-8156-0427-1	July 9, 2021 (digital)[13] March 29, 2022 (print)[14]	978-1-71-832682-8
4	March 13, 2020[15][16]	978-4-8156-0480-6 978-4-8156-0479-0 (SE)	October 29, 2021 (digital)[17] May 24, 2022 (print)[18]	978-1-71-832683-5
5	August 6, 2020[19]	978-4-8156-0623-7	January 14, 2022 (digital)[20] August 2, 2022 (print)[21]	978-1-71-832684-2
6	December 10, 2020[22][23]	978-4-8156-0781-4 978-4-8156-0780-7 (SE)	April 15, 2022 (digital)[24] January 17, 2023 (print)[25]	978-1-71-832685-9
7	March 12, 2021[26][27]	978-4-8156-0783-8 978-4-8156-0782-1 (SE)	July 8, 2022 (digital)[28] April 18, 2023 (print)[29]	978-1-71-832638-5
8	August 12, 2021[30][31]	978-4-8156-1014-2 978-4-8156-1013-5 (SE)	October 7, 2022 (digital)[32] August 8, 2023 (print)[33]	978-1-71-832640-8
9	January 15, 2022[34][35]	978-4-8156-1227-6 978-4-8156-1226-9 (SE)	January 12, 2023 (digital)[36] June 11, 2024 (print)[37]	978-1-71-832688-0
10	October 15, 2022[38][39]	978-4-8156-1600-7 978-4-8156-1599-4 (SE)	August 4, 2023 (digital)[40] December 10, 2024 (print)[41]	978-1-71-832644-6
11	March 15, 2025[42]	978-4-8156-1912-1	—	—

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 nine tankōbon volumes as of March 2025.^[2] The manga is published in North America by Comikey and Square Enix through the global version of Manga Up!.

No.	Japanese release date	Japanese ISBN
1	August 6, 2020[43]	978-4-75-756754-2
2	November 7, 2020[44]	978-4-75-756929-4
3	June 7, 2021[45]	978-4-75-757298-0
4	January 7, 2022[46]	978-4-75-757550-9
5	July 7, 2022[47]	978-4-75-758011-4
6	February 7, 2023[48]	978-4-75-758388-7
7	September 7, 2023[49]	978-4-75-758770-0
8	July 5, 2024[50]	978-4-75-759288-9
9	March 7, 2025[51]	978-4-75-759602-3

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.^[2] The series will be produced by Blade and directed by Kazuomi Koga, with Touko Machida handling the series composition, Katsuyuki Sato serving as the character designer, and Tsugumi Tanaka, Kaho Sawada, Kanade Sakuma and Hanae Nakamura composing the music.^[52] It is set to premiere in October 2025 on the NUMAnimation programming block on TV Asahi and its affiliates, as well as BS11.^[53][54]

See also

• Days with My Stepsister, a mixed-media project by the same author.
• Spy Classroom, another light novel series illustrated by the same illustrator.