Monster Kingdom: Jewel Summoner is an RPG by Cozy Okada focusing on monster collection and battles. It contains a complex system of elements, monster evolution and enchanting. That system allows the player to fiddle with endless combinations to create a perfect group of hybrid monsters.

The player takes on the role of Vice, who is on a path to find the winged abomination that killed his mother. To do so he needs to became a Jewel Summoner. During his travels he will meet other jewel summoners and some of them will join him in his quest. Each character can call up to three monsters during a fight and swap them while battling. The creatures all belong to a certain elements. There are two main groups: light and dark, and then further broken down. The element influences the confrontations in a rock-paper-scissors scenario.

The game features over 100 unique monsters, and includes ad-hoc wireless connectivity to battle players or trade jewels.