The upcoming TV anime In a World Full of Zombies I’m the Only One Who Doesn’t Get Attacked has revealed its opening theme song ahead of its January 2027 premiere. Music project RetBear will perform “No Reaction,” a new track produced by Kairiki Bear, the Vocaloid creator known for songs such as “Venom” and “Darling Dance.”
The announcement was made on October 10, which is also known as World Zombie Day. Alongside the theme song reveal, the anime’s key visual and main promotional video have been released, offering fans an early look at the adaptation.
The series is scheduled to begin airing on AT-X in January 2027. Its source manga has recorded more than 9.5 million downloads and sold over 750,000 copies, including spin-offs. The upcoming adaptation brings the zombie-themed story to television while reuniting RetBear with the anime industry for its first new song in nearly four years.
RetBear is a music project led by Kairiki Bear, whose YouTube channel has surpassed 470 million total views, according to the announcement. The project pairs the producer with a different anonymous vocalist for each release. For “No Reaction,” the vocalist is credited as unknown Vo: 0in, while RetBear handles the lyrics, composition, and arrangement.
RetBear previously contributed opening themes to Black Summoner with “Mannaka DEAD END” and REVENGER with “Down Timer.” The new song marks the project’s first release in nearly four years since “Down Timer” arrived in January 2023.
Fans can watch the anime’s main promotional video on YouTube. Digital streaming details for “No Reaction” have not yet been announced.
