Kairiki Bear, a popular vocaloid producer who is known for hits such as “Venom” (44 million views on YouTube) and “Darling Dance” (22 million views), launched a new project called Retbear in June 2022. Retbear is an “anonymous” unit that combines Kairiki Bear with a different unknown vocalist for each song. The guest vocalist performs under a different name from usual. Retbear’s debut song will be “Atamannaka DEAD END” (unknown Vo: 10fu), the opening theme of the TV anime Black Summoner. The new opening theme was recently revealed in the anime’s second official trailer.

Black Summoner, which will be broadcast from July 2022 in Japan, is an adaptation of a popular isekai series about a battle junkie published by Overlap Bunko, which has sold more than 1.4 million copies and has over 280 million views on the novel posting website Shōsetsuka ni Narō. In addition to the information on the opening song, it was also announced that the ending theme will be sung by Minori Suzuki, who plays the role of Sera in the anime.