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

Main characters

• Akiteru Ooboshi (大星 明照)
• [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)
• [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. 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)
• [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).
• Ozuma Kohinata (小日向 乙馬)
• [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)
• [2]
• Sumire is Akiteru's mathematics and homeroom 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). She is often late in finishing her work, much to Akiteru's chagrin.
• Reiku Otoi (音井 麗紅)
• Reiku is a second year high school student. She is a sound engineer.
• Midori Kageishi (影石 翠)
• [3]
• Midori is Sumire's little sister and the President of the Drama Club.
• Kanaria Kiraboshi (綺羅星 金糸雀)
• An idol and a famous editor at UZA Publishing, whose real name is Kana Hoshino.
• Sasara Tomosaka (友坂 茶々良)
• A first year high school student. She is an influencer on Pinstagram.

Supporting characters

• Makoto Tsukinomori (月ノ森 真琴)
• 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)
• Otoha is the mother of both Ozuma and Iroha.
• Kou Kageishi (影石 鉱)
• Sumire and Midori's Grandfather.
• Mizuki Tsukinomori (月ノ森 海月)
• Mashiro's mother.
• Asagi Tachibana (橘 浅黄)

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]

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 ten tankōbon volumes as of October 2025.[2] 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.[2] 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.[54] The series aired from October 5 to December 21, 2025, on the NUMAnimation programming block on TV Asahi and its affiliates.[55][56] The opening theme song is "Uza Kawaikute Nani ga Warui!" (ウザ可愛くて何が悪い！), performed by Karubi Akami, while the ending theme song is "Hoshi no Kodō" (星の鼓動), performed by Kohana Lam.[57] Crunchyroll streamed the series.[58]

Episodes