He was born from Shouta's dreams to become a painter. However, as tragedies occured in Shouta's family, his dreams began to fade away along with Kuuta.
A half-year after Shouta moved away with his parents, Kuuta remained in the manor and began wreaking havoc to make people notice. As the rumors finally reach the Guardians, they decide to take a look at Shouta's old house and investigate. At the same time, Shouta returns to visit his old house, but his depression turns Kuuta into an X-Character.
After Amulet Spade purifies him, he returns to his master, with his hopes and dreams revived.
At the end of the episode, we see Shouta sitting in front of a blank painting board and he smiles, reaching his hand to his chest. In the next scene, we see Kuuta's egg rustle, ensuring that it'll hatch one day again.
As an X-Character, he can attack with a paintbrush using an attack called "Dark Canvas". When he uses it, he releases painting substance from his paintbrush.
Because Kuuta is an artistic character, his powers are quite similar to Miki's.
- Shouta was unable to see Kuuta, however his grandfather could. This shown when Shouta opens his grandfather's drawing book and Kuuta is drawn beside him.