A spin-off anime series based on the Slime Diaries: That Time I Got Reincarnated as a Slime manga was scheduled to premiere in January 2021 but was delayed to April 2021 due to COVID-19.[16] The series aired from April 6 to June 22, 2021. Eight Bit also animated the series, with Yuji Ikuhara directing the series, Kotatsumikan writing the scripts, Risa Takai and Atsushi Irie as character designers, and R.O.N composing the music.[17]