# 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) 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.

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

### 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 "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, Kageishi Sumire)

    Voiced by: Kana Hanazawa
    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
    Midori is Sumire's little sister and a member of the theater club.

## 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.
| No. | Original release date | Original ISBN | English release date | English ISBN |
| 1 | April 12, 2019 | 978-4-8156-0187-4 | February 10, 2021 (digital) December 7, 2021 (print) | 978-1-71-832680-4 |
| 2 | July 12, 2019 | 978-4-8156-0277-2 | April 23, 2021 (digital) February 1, 2022 (print) | 978-1-71-832681-1 |
| 3 | November 14, 2019 | 978-4-8156-0427-1 | July 9, 2021 (digital) March 29, 2022 (print) | 978-1-71-832682-8 |
| 4 | March 13, 2020 | 978-4-8156-0480-6 978-4-8156-0479-0 (SE) | October 29, 2021 (digital) May 24, 2022 (print) | 978-1-71-832683-5 |
| 5 | August 6, 2020 | 978-4-8156-0623-7 | January 14, 2022 (digital) August 2, 2022 (print) | 978-1-71-832684-2 |
| 6 | December 10, 2020 | 978-4-8156-0781-4 978-4-8156-0780-7 (SE) | April 15, 2022 (digital) January 17, 2023 (print) | 978-1-71-832685-9 |
| 7 | March 12, 2021 | 978-4-8156-0783-8 978-4-8156-0782-1 (SE) | July 8, 2022 (digital) April 18, 2023 (print) | 978-1-71-832638-5 |
| 8 | August 12, 2021 | 978-4-8156-1014-2 978-4-8156-1013-5 (SE) | October 7, 2022 (digital) August 8, 2023 (print) | 978-1-71-832640-8 |
| 9 | January 15, 2022 | 978-4-8156-1227-6 978-4-8156-1226-9 (SE) | January 12, 2023 (digital) June 11, 2024 (print) | 978-1-71-832688-0 |
| 10 | October 15, 2022 | 978-4-8156-1600-7 978-4-8156-1599-4 (SE) | August 4, 2023 (digital) December 10, 2024 (print) | 978-1-71-832644-6 |
| 11 | March 15, 2025 | 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. 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 | 978-4-75-756754-2 |
| 2 | November 7, 2020 | 978-4-75-756929-4 |
| 3 | June 7, 2021 | 978-4-75-757298-0 |
| 4 | January 7, 2022 | 978-4-75-757550-9 |
| 5 | July 7, 2022 | 978-4-75-758011-4 |
| 6 | February 7, 2023 | 978-4-75-758388-7 |
| 7 | September 7, 2023 | 978-4-75-758770-0 |
| 8 | July 5, 2024 | 978-4-75-759288-9 |
| 9 | March 7, 2025 | 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. 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. It is set to premiere in October 2025.