Genki is a boy who loves playing the Monster Rancher games and one day he's somehow transported into the world of the video game where he meets the girl Holly and the monsters Mochi, Suezo, Golem, Tiger and Hare. Together, they are searching for a way to revive the Phoenix, which is the only monster capable of stopping the evil Moo.
Genki and his friends reach a town with a giant coliseum! Tiger battles Hare, who cheats his way to a victory. Genki and the others soon forgive him and Hare offers to buy them dinner and a place to stay the night. In the morning, Hare runs off and leaves them the bill, but Tiger catches up and makes him pay. Hare apologizes, and joins the group.
Genki and his friends come across a beautiful valley with a small village at the foot of a dam. When Moo's troops damage the dam, Genki and the monsters must work together to save the town from utter disaster!
Holly's past is finally revealed! She shares her story with the gang on a miserable, rainy day. She tells of how she came to be on the quest for the Phoenix with Genki and the others.
Genki and his friends continue their journey, and find a huge canyon, as well as a beat-up airplane. They take the plane, but has Genki been double-crossed by the pilot? The group must fend off the evil Kuro in order to get out of this predicament.
Genki and friends arrive in Heaven Canyon via the iron bird. In the canyon are humans mining “mystery disks” under the oppression of Moo. Are Genki and his friends strong enough to defeat them and free the imprisoned humans?
After scaling a cliff, Genki and Mocchi must free their captured comrades and find a way to defeat Clay, Pixie, and Big Blue!