- Onii King (Onii Kingdom)
- King Duvroc (Kingdom of The Jolly)
- King Shishkebaboo (Ripe Kingdom)
- King Omelet (Worrywart Kingdom)
- TV Dinnah (Primetime Kingdom)
- Long Sauvage (Tiptoe Kingdom)
- Jumbo Champloon (New Island)
Each of the Kings is named after a food or drink, as is the case with the rest of the main cast of Little King's Story. (Main Article: Etymology)
Along with Kings, there are Guardian UMA that protect Forests. Defeating one will allow Corobo to build villages and cities in the land where the forest once stood. Only Cow Bones, the Onii Man, and either the Clockwork Knight or the Blue Dragon are necessary to finish the game, while the rest are optional.
- Cow Bones (Ruined Turnip Field, Cemetery, Turnip Forest, Over-there-Beach)
- Onii Man (Meadow over the Bridge, Onii Grounds)
- Yvonne (Upchuck Forest)
- Clockwork Knight (Wavy Rock Forest)
- Owl Hag (Owl Forest)
- Ogre Ergo (Torn Forest)
- Mush Bro (Mushroom Forest)
- Mush Geezer (Shadow Forest)
- Radeeze (Red Turnip Forest)
- Blue Dragon (Small Lot)
Some sidequests involve fighting bosses that do not affect the main story.
After defeating all the Kings, a new objective begins which results in King Corobo fighting one final opponent.