Kazuma has blonde, unkempt hair and light brown teary eyes. He is generally seen as the "cry baby" of the bunch and is seen with rosy pink cheeks. He is the identical twin of Takuma and is always seen holding his hand or following him around.
He is the more conservative and fearful twin of the two, and he shares these traits as his father, Kousuke. He is easily startled by new things and cries easily in almost every situation, needing comfort from his twin brother frequently. He generally needs ample encouragement to do the things that he wants and is dependent on his brother to help him. Thus, he forms a strong bond with his twin even though he is easily discouraged at times when his brother's straightforward personality leads to him saying hurtful words.
He is generally an agreeable toddler, avoiding conflict with the other children. He often mimicks Takuma's words and actions when interacting with them in the daycare room.
Kazuma is the younger, identical twin of Takuma, His mother, Umi, is the P.E. teacher at the school while his father, Kousuke is a famous actor who often visits the twins in disguises at the babysitter club.
- Uma from Kazuma's name, means "horse"
- In Taka's "Ranger Five" game, Takuma and him are "Ranger Yellow" concurrently.
- In the anime, he is voiced by Tanezaki Atsumi.