In its first two mini-episodes, Isekai Quartet is content to let its audience bask in the sheer absurdity and awesomeness of watching characters from four of their favorite Isekai anime bounce off one another in a school setting. Their homeroom teacher, Roswall L. Mathers from Re:Zero, begins with introductions.
Ram notes that Kazuma, who is staring at “Barusu,” is wearing the same bizarre threads we know to be an IRL track suit. Little do both Kazuma and Subaru know that Ains Ooal Gown is also one of them, as is Tanya, but in different forms. I did enjoy Kazuma and Subaru’s reaction to Tanya’s very militaristic group’s introduction.
Since both OverLord and KonoSuba feature very similar fantasy races and spells, Aqua takes it upon herself to launch a preemptive attack on the Nazarick crew, since they consist of an undead, a vampire, a demon, and a monster. Momonga even recognizes the name of her spell, which he expects to be low-level, but actually hurts like a bitch.
Even more disconcerting to the guardians and their ruler is that Kazuma is able to simply bop someone as powerful as Aqua on the head and drag her off, scolding her for attacking her classmates. The next day, she has to stand in the hall with three water buckets, an ironic punishment for the water goddess.