The upcoming anime adaptation of Backstabbed in a Backwater Dungeon: My Trusted Companions Tried to Kill Me, But Thanks to the Gift of an Unlimited Gacha I Got LVL 9999 Friends and Am Out For Revenge on My Former Party Members has revealed its full main cast, confirming eight voice actors set to bring the revenge fantasy to life. The series, often shortened to Mugen Gacha, is slated to premiere on October 3, 2025.
Produced by J.C.Staff, the anime is based on the popular light novel series by Shisui Meikyo and illustrator tef.
Main Cast Brings Betrayed Protagonist and Powerful Allies to Life
Leading the charge are Nina Tamaki as the protagonist Light, and Ikumi Hasegawa as Mei, the formidable Level 9999 fighter who emerges from the Unlimited Gacha. They are joined by six newly announced voice actors, rounding out the core ensemble of characters.
Newly Announced Voice Actors
The recently unveiled cast members include:
- Hana Hishikawa as Nazuna
- Shiori Izawa as Aoyuki
- Ayumi Mano as Ellie
- Yuko Natsuyoshi as Nemumu
- Katsuya Miyamoto as Gold
These additions complete the roster of primary characters set to appear in the highly anticipated adaptation.
Plot Overview: Betrayal, Survival, and Vengeance
The story follows Light, an adventurer who is brutally betrayed and left for dead by his trusted companions deep within the dangerous Abyss dungeon. Miraculously surviving, Light utilizes his unique skill, the “Unlimited Gacha,” which previously only yielded junk items. This time, however, it summons Mei, a powerful Level 9999 fighter in a maid outfit.
Over three years, Light establishes his own kingdom within the dungeon, assembling a loyal party of powerful, Level 9999 warriors summoned through his gacha ability. Now an overlord himself, Light prepares to ascend to the surface world to exact his revenge on those who betrayed him. J-Novel Club licenses the light novels in English and describes the series as a tale of betrayal and ultimate retribution.
Production Details and Creative Team
The anime is directed by Katsushi Sakurabi (known for Flying Witch and The Betrayal Knows My Name) at J.C.STAFF. Hiroshi Ohnogi (Fullmetal Alchemist: Brotherhood) is handling the series scripts, while Yukie Suzuki (Tsukimichi -Moonlit Fantasy-) is responsible for character designs. The sound direction is overseen by Yoshikazu Iwanami (Ajin, Fate/Zero), and Ryō Takahashi (High Card, Wind Breaker) is composing the music.
Additional staff members include Yukiko Ashino (Studio Tulip) as art director, Tomomi Ando as color designer, Shingo Fukuyo as photography director, and Maki Sendo (REAL-T) as editor. Lantis is in charge of music production, with Yasumasa Koyama handling sound effects.
Release Information
Backstabbed in a Backwater Dungeon will begin airing on October 3, 2025, on Tokyo MX, MBS, and BS11 channels in Japan. An advance screening of the first three episodes is scheduled for September 7 at Shinjuku Piccadilly Cinema. Fans can anticipate the series to bring the thrilling revenge saga to screens this fall.
