蛇神くんは寒いと変身しちゃうから

Hebigami is a new transfer student with a strange condition: whenever he gets cold, he turns into a snake! He’s feared by nearly all his classmates for his mysterious aura, but his seatmate Haruna knows his true kind nature. Since he can’t return to his human form until his body temperature is high enough, Haruna takes it upon herself to warm him up! A slow-burn, heartwarming, and youthful romcom about a nonhuman boy and an ordinary high school girl. (Source: Manga UP!)