How about introducing the character from the pool in Block A (the one in the photo)? We know Ren was banned while streaming, but let's say Ren decided to play games and watch something unbanned. She discovers a girl online who makes the same content as her, with some differences. Researching her, she finds out she works as a coach at the pool. Ren decides to confront her about the content theft, but discovers she's quite a nice person. The pool coach offers to help with the training as compensation for the content theft. That's all I've got, what do you think?