The official website for the live‑action movie My Sister’s Boyfriend (Japanese title Onē‑chan no Midori‑kun) announced that actor Taisuke Niihara, known for At 25:00 in Akasaka and Young & Fine, will appear as Amamiya, a freshly hired assistant producer at the TV station where the older sister Momo works.
Amamiya’s role is expected to intersect with the series’ main workplace drama, providing additional comic moments and plot twists that complement the central love‑triangle. Niihara’s previous live‑action experience in Amu Meguro‘s works will likely help him blend into the film’s tone, which balances teenage romance with light‑hearted workplace humor.
The movie adapts Amu Meguro’s Midori Loves My Sister manga, originally serialized in Shueisha’s Bessatsu Margaret beginning in 2022. The story follows junior‑high student Sui Sanae, who reluctantly tolerates her older sister’s boyfriend Midori‑kun. When Midori is unexpectedly hired as Sui’s home tutor, the pair discover hidden layers to each other’s personalities, sparking a blend of conflict and affection that resonated with readers.
Beyond Niihara, the film’s ensemble features Masaki Hashimoto, a member of the idol group timelesz, portraying Midori Yukishiro. Hashimoto previously appeared in the live‑action drama Summer Complicity. Runa Nakajima takes on the role of Sui Sanae, bringing experience from the adaptation of Uchi no Otōto‑domo ga Sumimasen. Rinka Kumada, recognized for roles in Otonanajimi, Kimi ni Todoke, and It Takes More Than a Pretty Face to Fall in Love, plays Momo Sanae, Sui’s older sister and Midori’s girlfriend. Reo Matsumoto, known for I Cannot Reach You, appears as Ayame Mizukawa, Sui’s childhood friend.
Director Mahito Kimura—whose résumé includes the live‑action adaptations of Strobe Edge and Blue Spring Ride—heads the project, while screenwriter Nami Kikkawa (known for the Honey Lemon Soda film) crafts the script. Production oversight and distribution are handled by the veteran studio Shochiku, ensuring a wide theatrical rollout across Japan.
The film is slated to open in Japanese theaters on December 4, 2026. Fans can follow the official site for trailers, ticket information, and event updates at Shochiku’s Midori‑kun movie page. A promotional video shared on the film’s official X (Twitter) account further teases the chemistry between the lead cast and offers a glimpse of the film’s visual style.
Amu Meguro’s career extends beyond Midori Loves My Sister. She previously concluded the popular series Hinata no Blue in July 2021 and launched the long‑running Honey So Sweet in Shueisha’s Bessatsu Margaret from 2012 to 2015, a title that Viz Media later released in English under its Shojo Beat imprint. The success of Honey So Sweet even inspired a live‑action film that premiered in March 2018, demonstrating Meguro’s proven track record for cross‑media adaptations.
With a robust cast, seasoned crew, and a source material that has already captured a dedicated shōjo audience, My Sister’s Boyfriend looks set to become a notable entry in this year’s live‑action slate. The addition of Taisuke Niihara adds fresh energy to the ensemble, promising fans both new dynamics and familiar charm as the story moves from page to screen.
Featured image: ©2026「お姉ちゃんの翠くん」製作委員会
Source: Anime News Network