The upcoming “light anime” adaptation of the boys’ love isekai fantasy series, Saioshi no Gikei o Mederu Tame, Nagaikishimasu! (also known as “I’ll Live a Long Time In Order to Cherish My Favorite Step-Brother!”), has unveiled a new promotional video, additional cast members, key staff, and details about its ending theme. The series is set to begin its streaming debut on January 3, 2026, with broadcasts in Japan commencing on January 6, 2026.
New Promo Video Showcases Enchanting World and Character Dynamics
The newly released promotional video offers viewers a deeper look into the anime’s vibrant world and the intriguing relationship between its main characters. The trailer provides a glimpse of the narrative, which follows Alba, a young man reincarnated into an otome game as the step-brother of his most beloved character, Orsis. The visual presentation, handled by Imagica Infos and Imageworks Studio, sets an engaging tone for the highly anticipated adaptation.
Expanded Voice Cast and Production Team Detailed
The anime has confirmed its primary voice cast and added new members to its roster. Ayumu Murase will lend his voice to the protagonist, Alba, while Shouta Aoi is cast as Orsis, Alba’s cherished step-brother.
Further expanding the cast, the newly announced voice actors include:
- Reo Tatsumori as Harus
- Maaya Torigoe as Floro
- Yuya Hirose as Bruno
Behind the scenes, Yusuke Morishita is directing the light anime. Izumi Tezuka is responsible for the series composition. The animation production is a collaborative effort between Imagica Infos and Imageworks Studio. The original light novel series, which this anime adapts, was penned by Tenma Asahi with illustrations by Kazuaki.
Shouta Aoi Also Performs the Ending Theme, “Endless You”
In addition to his role as Orsis, voice actor Shouta Aoi will also perform the ending theme song for the series, titled “Endless You.” A sample of the song is featured in the recently released trailer.
Streaming Debut Set for January 3, 2026
Fans eagerly awaiting the adaptation can look forward to its streaming premiere on January 3, 2026. The television broadcast in Japan will officially begin on January 6, 2026. This “light anime” is the inaugural project from BALLOON, a boys’ love animation label formed by IMAGICA Infos in collaboration with Dai Nippon Printing, CYBIRD, and Blue Rights.
Understanding ‘Saioshi no Gikei o Mederu Tame, Nagaikishimasu!’
The story of Saioshi no Gikei o Mederu Tame, Nagaikishimasu! centers on a young man who finds himself reincarnated as Alba, the son of an impoverished aristocratic family within his favorite otome game. To his delight, he discovers that Orsis, his most beloved character from the game, is now his new step-brother through marriage. However, Alba soon remembers that his character is destined for a tragic death, which in turn leads to Orsis losing his smile. Determined to avoid this fate and continue doting on Orsis, Alba embarks on a mission to dodge all death flags and live a long life.
The original light novel series, written by Tenma Asahi and illustrated by Kazuaki, began as a web novel in September 2021 before being published by AlphaPolis. A manga adaptation by Aki Tsujimoto also launched in January 2024.
