Kaketa Tsuki no Mercedes

Mercedes and the Waning Moon is a TV anime set to premiere in January 2027. It is based on a light novel series written by Firehead, who also wrote A Wild Last Boss Appeared!, with art by KeG. The story first ran as a free web novel on the site Shosetsuka ni Naro from 2018 to 2022. TO Books began printing it in 2021, and a manga version drawn by Pochi Edoya started the same year. By July 2026 the series had more than 200,000 copies in print. In English, J-Novel Club publishes both the novels and the manga. The full Japanese title roughly means that a girl was reborn as a vampire noble, was about to be thrown away, and so decided to conquer dungeons.

The anime is made by the studio Teddy. Kunihisa Sugishima is the director, Jun Kumagai is in charge of series composition (planning the story across episodes), and Nami Shoyama designed the characters. The music is by R.O.N and Shuhei Mutsuki. Anna Nagase voices the main character, Mercedes.

Mercedes Grunewald was a person from Japan in her past life. That life ended without her ever feeling happy or satisfied. Now she has been born again as a vampire in a land ruled by vampires. Her father is a rich noble, but her mother is only a concubine, which means a partner the father never married in the official way. The rest of the family treats her mother coldly, and Mercedes knows from a very young age that she will never be chosen to take over the family. Someday, she and her mother could be pushed out with nothing.

Mercedes looks at her small household and sees a problem. Her mother has no work skills. Their only maid is getting old. And Mercedes herself is still just a little child. If no one else will protect them, she decides that she must do it. So, while she is only about the age of a kindergarten student, she starts training for a job that is open to anyone: exploring dungeons. Dungeons are dangerous underground mazes full of monsters and treasure. Because Mercedes is a vampire, her body has the power to grow much stronger than a normal human child's.

The story mixes action and fantasy adventure with family drama. At its center is a tough, clear-thinking girl who refuses to wait for someone to save her. Instead of wanting fame or revenge, she fights for something simple and personal: a safe life for her mother and a life that feels complete this time. The title's image of a waning moon, a moon that is not full, fits this goal, since Mercedes hopes to find whatever will make her life feel whole.