Digimon: Digital Monsters

It's the year 2020. The Network has become something humans can no longer do without in their daily lives. But what humans don't know is that on the other side of the Network is the Digital World, a realm of light and darkness. Nor are they aware of the Digimon who live there. Fifth grader Taichi Yagami's mother and little sister Hikari went to Shibuya, and now they're aboard a runaway train. Taichi hurries to Shibuya to save his mother and sister, but the instant he heads toward the station platform... a strange phenomenon befalls the DigiDestined, and Taichi goes to the Digital World!

Centers on the lives of creatures called Bakugan and the battle brawlers who possess them.

Isekai'd into another world, Haruka makes use of seemingly underpowered skills to live as a lone wolf.

Nakajima Youko is your average somewhat timid high school student. One day, a strange man named Keiki appears before her, swearing allegiance. Before she could properly register what was happening, demon-like creatures attack Youko and her friends, after which they are pulled into a different world. A world unlike what she has ever known. Separated from Keiki, Youko and her friends must do whatever they can if they wish to survive in this new world.