I added a line that made his head shape different. Also, I'm showing off his abilities. He summons 4 familiars when he unleashes his power, and these spheres are entirely composed of heat. These can be used to unleash fire. On the right, he uses it for combat. On the left, he uses the thermal energy like rocket fuel.

One interesting note is that he needs to absorb thermal energy to use his power, and he stores it like a battery. He sometimes uses this to simulate warm-bloodedness so he doesn't freeze to death in cold places. Daichi can store up a lot of thermal energy, but it drains very quickly during any combat or "showing off". That being said, recharging the heat is pretty easy. He can consciously choose and drain heat from most sources within about 7 meters. He can even stick his hand in a campfire, and the rate at which he drains the heat will prevent him from burning himself (If it was something more intense like a kilm or a welding torch, he wouldn't be able to keep up). Subconsciously, he barely drains any heat. This is the kind of laws his magic follows.