The highly anticipated anime adaptation of Shisui Meikyou and tef’s light novel series, 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 and the World, has unveiled additional cast members, key staff, and confirmed an October 3 premiere date. Bandai Namco Filmworks made the announcement on Friday, revealing a new key visual alongside the details. The series, often shortened to Mugen Gacha, will air on Tokyo MX, MBS, and BS11 channels.
New Additions to the Cast
The anime adaptation is expanding its voice acting ensemble with several notable talents. The newly announced cast members include:
- Hana Hishikawa as Nazuna
- Shiori Izawa as Aoyuki
- Ayumi Mano as Ellie
- Yūko Natsuyoshi as Nemumu
- Katsuya Miyamoto as Gold
These voice actors will join the previously announced main cast, which features Nina Tamaki as Light, the protagonist, and Ikumi Hasegawa as Mei.
Behind the Scenes: The Production Staff
The creative team bringing Backstabbed in a Backwater Dungeon to life includes a blend of experienced professionals. Katsushi Sakurabi (known for Flying Witch and The Betrayal Knows My Name) is directing the series at studio J.C.STAFF.
The newly revealed staff members are:
- Art Director: Yukiko Ashino (Studio Tulip)
- Color Design: Tomomi Andō
- Compositing Director of Photography: Shingo Fukuyo
- Editing: Maki Sendo (REAL-T)
- Sound Effects: Yasumasa Koyama
- Music Production: Lantis
Previously announced key staff include Hiroshi Onogi (Fullmetal Alchemist: Brotherhood) handling series composition, Yukie Suzuki (TSUKIMICHI -Moonlit Fantasy-) on character designs, and Ryo Takahashi (WIND BREAKER) composing the music. Yoshikazu Iwanami is serving as the sound director.
Plot Overview and Anticipation
The Backstabbed in a Backwater Dungeon anime is based on the popular light novel series by Shisui Meikyou and tef. The story follows Light, who is betrayed and seemingly killed by his trusted companions and kicked out of the Concord of the Tribes. He narrowly escapes and finds himself in the Abyss, the most perilous dungeon in the realm. Using his unique “Unlimited Gacha” skill, which initially yielded only junk items, he summons Mei, a powerful Level 9999 fighter, among other strong allies. Three years later, Light has established his own dominion within the dungeon and, now a Level 9999 Overlord himself, plans his revenge on those who betrayed him.
The series gained a dedicated following through its light novel and subsequent manga adaptation. An advance screening of the first three episodes is scheduled for September 7 at Shinjuku Piccadilly Cinema, giving fans an early look at the revenge-fantasy adventure. The anime was initially announced in November 2024 as part of Hobby Japan Novels’ 10th-anniversary celebrations, with a Fall 2025 broadcast window confirmed in April 2025.
