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) is 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 has been announced.

Characters

 * Akiteru Ōboshi (大星 明照)
 * 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.
 * 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)
 * 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 cannot read the atmosphere. She aims to become a voice actress.
 * 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 cannot read the atmosphere. She aims to become a voice actress.


 * Mashiro Tsukinomori (月ノ森 真白)
 * 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.
 * 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.


 * Ozuma Kohinata (小日向 乙馬)
 * Ozuma is a second year high school student. In the story, Ozuma is a kind and caring person. He is described as "beautiful 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.
 * Ozuma is a second year high school student. In the story, Ozuma is a kind and caring person. He is described as "beautiful 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)
 * Sumire is Akiteru's subject teacher. She is described as a ruthless guidance and has a poisonous tongue. She secretly works as an illustrator.
 * Sumire is Akiteru's subject teacher. She is described as a ruthless guidance and has a poisonous tongue. She secretly works as an illustrator.


 * Midori Kageishi (影石 翠)
 * Midori is Sumire's little sister.
 * Midori is Sumire's little sister.

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; ten volumes have been released as of October 2022. 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 eight tankōbon volumes as of July 2024. The manga is published 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. At the "GA Fes 2024" livestream event on March 10, 2024, it was announced that the series will be produced by Blade and directed by Kazuomi Koga, with Touko Machida handling the series composition, and Katsuyuki Sato serving as the character designer.