Monster Rancher

Genki is a boy obsessed with the Monster Rancher games until one day, he mysteriously finds himself pulled into the game's world. There, he meets a girl named Holly and a group of monsters-Mochi, Suezo, Golem, Tiger, and Hare. Their mission is to find a way to bring the Phoenix back to life, the only creature powerful enough to defeat the villainous Moo.