First making an appearance in Episode 7: Into the Jungle, the three kittens are introduced while being carried by a large Pterodactyl until rescued by Kutal, Mushra, and Sago. Rei and Sen present themselves as twins who "have been together since their lives began and will be together to the very end." Estie adds to it that "she is not a twin, but just younger" and agreed that she was everyone's favorite. Now reunited with Kutal, they find themselves wanting to stay with their family.