Hang in There! Saijou-kun.

A transfer student arrives in Class 1C of Shirakaba High School in Sapporo. His name is Nishijo-kun. He was born and raised in Wanda Town in eastern Hokkaido, his favorite food is pickled plums, and his special skill is "trying his best"—a perfectly ordinary high school student. But there was something about him that was a little, no, very different from everyone else. That was his appearance. He had a round body like a big rubber ball, with a face, hands and feet, and a few strands of hair growing on top. What exactly is the true identity of Nishijo-kun, who looks like an alien or a ghost...!?