If you're looking for anime similar to Isekai Quartet Relay PV, you might like these titles.
The story follows Mihiro and begins on a day like any other. Mihiro bumps heads with a pet dog and loses consciousness. When she wakes up, she finds herself in a mysterious animal world. Mihiro discovers the shocking truth of her new situation and starts work at an animal pawn shop. She sets her sights on the day she can leave the shop and return to her former world.
Need a happy Break Time to distract you from the pain of Re:ZERO proper? These Re:ZERO shorts feature all of your favorite characters: Subaru, Emilia, Rem, Ram, Felt, and the rest of the gang, able to take a moment away from curses and cults for long enough to enjoy one another's company ~
Subaru awakens to find himself in a classroom... with Emilia as the homeroom teacher?