A Ninja and an Assassin Under One Roof, also known as NinKoro, is a Japanese manga series by HundredBurger that has been serialized in ASCII Media Works’ shōnen manga magazine Comic Dengeki Daioh “g” since February 2021. An anime television series adaptation produced by Shaft premiered in April 2025. The series is directed by Yukihiro Miyamoto, with series composition by the staff of Shaft under the collective pseudonym Fuyashi Tou, character designs by Kazuya Shiotsuki, and music composed by Ryūnosuke Kasai.
Plot and Characters
The story follows Satoko Kusagakure, a ninja who escapes her village, and Konoha Koga, a high school student who is secretly an assassin. Konoha rescues Satoko, and they begin living together. Satoko uses her ninja skills to help Konoha clean up after her assassinations, and Konoha protects Satoko from pursuers from her village.
- Satoko Kusagakure: A ninja who fled her village. She is naive and possesses the ability to transform objects using ninjutsu. Voiced by Haruna Mikawa.
- Konoha Koga: A high school student and professional assassin. She saves Satoko and offers her a place to stay. Voiced by Kana Hanazawa.
Other Characters:
- Marin Izutsumi: A rival assassin who initially kidnaps Satoko to exploit her skills. Voiced by Yuu Serizawa.
- Kuro: Satoko’s leader from her ninja village. Voiced by Eri Kitamura.
- Yuriko: Kuro’s partner. Voiced by Rumi Ookubo.
- Roboko: A robot duplicate of Satoko created by Marin. Voiced by Haruna Mikawa.
Episode 5 Recap: Roboko’s Farewell
In episode 5, titled “A Robot and an Assassin Under One Roof,” Marin Izutsumi, a rival assassin, seeks to surpass Konoha in the rankings. She kidnaps Satoko and replaces her with a robot duplicate named Roboko. Konoha fails to notice the switch and develops a stronger bond with Roboko. After a month, Konoha accuses the real Satoko of being fake. Roboko then betrays Marin. Satoko ultimately proves her identity by turning Roboko into leaves, leaving Konoha devastated.
Episode 6: A Busty Girl and an Assassin Under One Roof
Episode 6, titled “A Busty Girl and an Assassin Under One Roof,” premiered on May 15, 2025. Following Roboko’s destruction, Satoko and Konoha’s relationship becomes strained. Konoha is dealing with the loss of her best friend, Roboko, while Satoko feels like an inferior imitation.
Satoko’s Transformation
Satoko, seeking a quick fix to regain Konoha’s attention, decides to become more like Roboko. She fixates on the idea of having large breasts, believing it will make her more useful to Konoha. Inspired by a ninja with the ability to store a giant sword in her cleavage, Satoko seeks a way to achieve similar results.
Marin’s Return and Breast Storage Ninjutsu
With the help of Marin’s invention, Satoko attempts a new ninja skill: Breast Storage Ninjutsu. However, her new, larger breasts prove to be impractical and an annoyance.
Konoha’s Realization
Through Satoko’s failed attempts, Konoha realizes that both Satoko and Roboko genuinely care for her and are doing their best to support her. Konoha understands that both Satoko and Roboko’s feelings come from the same place.
Themes and Analysis
Episode 6 explores themes of identity, loss, and the complexities of relationships. It uses comedy to address serious topics and delve into the characters’ emotions. The episode also touches on the idea of feeling unwanted and the desire to be useful in a relationship.
Fan Reception
The episode has been well-received by fans, with many praising its humor and emotional depth. Some have lauded the show’s ability to address serious topics through comedic situations. The unexpected plot twist of Satoko’s transformation has also been a point of discussion.
Where to Watch
A Ninja and an Assassin Under One Roof is available for streaming on Crunchyroll.
Additional Information
- The anime is expected to run for 12 episodes.
- Seven Seas Entertainment has licensed the manga series for English publication, with the first volume set to release in December 2025.
- The opening theme song is “Yarenno? Endless” performed by Kana Hanazawa, and the ending theme song is “NinKoro Dance” performed by HoneyWorks feat. HaKoniwalily.
