Shunsuke Takeuchi joins I Left My A-Rank Party as new character mastoma – What to expect in episode 15

The ongoing I Left My A-Rank Party to Help My Former Students Reach the Dungeon Depths! TV anime has added a new voice to its already impressive cast. Shunsuke Takeuchi, a popular voice actor, has officially joined the series, bringing the character Mastoma to life. Mastoma, a ruler from a distant land who is determined to marry Rain, will make his debut in Episode 15, scheduled to air on April 27, 2025. Fans got their first glimpse of Mastoma in Episode 14, where he made a brief cameo.
This exciting news comes as I Left My A-Rank Party continues the second part of its run, which premiered on March 22, 2025. With 24 episodes planned, the anime is set to offer even more thrilling adventures, battles, and character developments.
Episode 15 is set to be a game-changer! The much-anticipated debut of Mastoma is packed with tension. His arrival and his pursuit of Rain are bound to stir up some serious drama as the journey through dungeons continues. With each twist and turn, the stakes keep getting higher, and this new character is sure to bring fresh chaos to the mix.

Behind the scenes, Katsumi Ono directs, known for his work on Hypnosis Mic: Division Rap Battle – Rhyme Anima and Symphogear. The brilliant Kazuyuki Fudeyasu handles the script, bringing his talent from Shangri-La Frontier. The stunning character designs come from Masakazu Yamazaki (Birdie Wing – Golf Girls’ Story), with Akira Kikuchi leading the action sequences. Animation is powered by BN Pictures, ensuring each battle is an eye-popping spectacle.
Originally a web novel by Kosuke Unagi and illustrated by Super Zombie, I Left My A-Rank Party to Help My Former Students Reach the Dungeon Depths! began as a serialized story on the Shosetsuka ni Naro platform in October 2020. The light novel series, published by Kodansha, wrapped up with its fifth volume in February 2025.
The anime follows Yuke, a red mage who, after years of mistreatment by his former A-rank team, Thunder Pike, decides to take a stand and break free. He reunites with his former students Marina, Silk, and Rain, forming a new team, Clover. This new crew quickly rises to fame, with Yuke guiding them through some of the most challenging dungeons in existence.
The team’s ultimate goal? To conquer the dreaded Achromatic Darkness dungeon, one of the most dangerous places on the planet. As their fame spreads, they find themselves caught in a magical broadcast by the artifact Camelot, which brings a whole new level of danger and intrigue. The deeper they go, the more complex their journey becomes, threatening not just their lives, but the very world they’re trying to save.
The anime is streaming worldwide on Crunchyroll, bringing this captivating adventure straight to your screen. With subtitles in multiple languages, fans around the globe can join in the excitement. Whether you're into fantasy, thrilling dungeon crawls, or powerful character arcs, I Left My A-Rank Party offers it all.
New episodes are released regularly, so there's always something to look forward to as the story unfolds.
With Shunsuke Takeuchi stepping into the role of Mastoma, things are just getting started. The series promises even more surprises, character twists, and world-building as we move forward. Expect to see more action-packed dungeon runs, magical showdowns, and deeply emotional moments that will leave fans on the edge of their seats.