A fan-favorite romance manga is officially heading to theaters. The live-action adaptation of Onee-chan no Midori-kun, internationally known as My Sister’s Boyfriend, has revealed its first teaser visual, giving fans an exciting preview of the film ahead of its December 4, 2026 release in Japan.
The newly released visual also confirms the film’s main cast and offers the first peek of its heartfelt atmosphere. With anticipation continuing to grow, the adaptation is shaping up to bring the manga’s emotional slow-burn romance to life for audiences on the big screen.
Main Cast Brings the Story to Life
Masaki Hashimoto, a member of the idol group timelesz, will play Midori Yukishiro. The film marks his first leading role in a live-action movie.
Runa Nakajima has been cast as Sui Sanae. She is known for winning the Japan Academy Film Prize New Actor Award for TOKYO Taxi and also works as an exclusive model for Seventeen magazine.
Hashimoto said he was surprised to receive the lead role and was drawn to Midori’s complex personality after reading the manga. Nakajima shared that she was already a fan of the series and hopes to faithfully capture Sui’s emotional journey in the film.
Author and Director Share Their Thoughts
Manga creator Amu Meguro expressed her excitement about the live-action adaptation. She said she never expected the series to become a movie and was happy with the casting of Masaki Hashimoto as Midori.
The film is directed by Mahito Kimura, who is known for directing romance projects. He described the story as beautiful yet filled with emotional struggles, making it a romance that feels both gentle and realistic.
The screenplay is written by Nami Kikkawa, whose previous work includes Honey Lemon Soda. Together, the creative team aims to bring the manga’s emotional storytelling to the big screen.
First Teaser Highlights the Film’s Romance
The newly released teaser visual focuses on the growing relationship between Sui and Midori. It captures the quiet emotions that have made the manga popular among romance fans.
In the image, Midori gently lifts Sui’s chin with a pen while she looks up at him. The green background and bright blue sky create a soft and heartwarming atmosphere.
The teaser also reflects the story’s slow-burn romance and emotional tension. It gives fans their first look at how the manga’s heartfelt moments will be recreated in live action.
