Bandai Namco Filmworks has revealed a promotional video and teaser visual for the Shinjiteita Nakama-tachi ni Dungeon Okuchi de Korosarekaketa ga Gift “Mugen Gacha” de Level 9999 no Nakama-tachi o Te ni Irete Moto Party Member to Sekai ni Fukushuu & “Zamaa!” Shimasu! (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) TV anime. It’s also been confirmed that the anime will premiere in the Autumn of 2025.
[https://www.youtube.com/watch?v=aL3vxY0kU5s]
Sakurabi Katsushi is directing the anime is J.C. STAFF studios, and the anime will star Tamaki Nina as Light and Hasegawa Ikumi as Mei.
The anime is based on the Shinjiteita Nakama-tachi ni Dungeon Okuchi de Korosarekaketa ga Gift “Mugen Gacha” de Level 9999 no Nakama-tachi o Te ni Irete Moto Party Member to Sekai ni Fukushuu & “Zamaa!” Shimasu! light novel series by Meikyou Shisui and tef. Author Meikyou started the story in April 2020 on the Shousetsuka ni Narou website, and Hobby Japan published the first novel in May 2021, with illustrations by tef. The 12th novel in the series will be released on April 18th, 2025.
J-Novel Club publishes the novel series in English under the title 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, and it released the 10th novel digitally on March 27th, 2025.
The novel series inspired a manga adaptation by Oomae Takashi, which was published in May 2021 on Kodansha’s Magazine Pocket website. Kodansha published the manga’s first tankoubon volume in August 2021, and the 16th volume will be released on May 7th, 2025.
Seven Seas publishes the manga in English under the title Backstabbed in a Backwater Dungeon: My Party Tried to Kill Me, But Thanks to an Infinite Gacha I Got LVL 9999 Friends and Am Out For Revenge, and it will release the manga’s ninth volume on August 12th, 2025.
J-Novel Club describes the novel’s story below:
When Light is kicked out of the Concord of the Tribes, his former comrades instantly turn on him. Light escapes this diabolical act of betrayal by the skin of his teeth…only to find himself in the deepest part of the Abyss, the most dangerous dungeon in the realm! To avoid being eaten by carnivorous monsters, he uses the Unlimited Gacha, his sole magical skill. But where it previously only produced junk items, this time Mei—a gorgeous Level 9999 fighter in a maid outfit—springs forth! Fast forward three years, and Light has carved out his own kingdom in this backwater dungeon, summoning more beautiful Level 9999 warriors who swear absolute fealty to him. Now a powerful Level 9999 Overlord himself, Light plans to ascend to the surface and take revenge on his betrayers one by one!
