Isekai Quartet (2019 - 2020)

The plot of the series "Isekai Quartet" revolves around a mysterious academy between worlds that lures new students from different dimensions. In their worlds, red buttons simply appear. When someone presses one out of curiosity, they are immediately transported to the school, from which they cannot leave until they finish their final class. Several boys and girls become victims of the buttons: Tanya, Konosuba, Overlord, Re:Zero, and others. Now they must figure out where and why they ended up there.