Isekai Quartet is a Japanese anime series that serves as a chibi-style crossover between the light novel series KonoSuba, Overlord, Re:Zero, and The Saga of Tanya the Evil.
See also: List of Isekai Quartet episodes, Isekai Quartet (season 2), Isekai Quartet (season 1), Studio Puyukai, List of isekai works, and Subaru Natsuki.