Isekai Quartet (Japanese: 異世界かるてっと, Hepburn: Isekai Karutetto) is a Japanese anime series that serves as a chibi-style crossover between the light novel series KonoSuba, Overlord, Re:Zero − Starting Life in Another World, and Saga of Tanya the Evil, all published by Kadokawa Corporation. The series aired its first season from April to June 2019. A second season aired from January to March 2020, including additional characters from The Rising of the Shield Hero and Cautious Hero: The Hero Is Overpowered but Overly Cautious. A third season has been announced.