100m.

He was born fast. He had nothing else, only the ability to run fast. It gave him "a place at school" and "a bridge between friends." That was all the boy had. Then he met another boy who ran to forget the hardships in life. He was not fast by any means, but he had passion. The passion was infectious, and he gradually came to feel the same excitement. But that was the beginning of the "abnormality."

The mad dash for that "100m"—

(Source: Shonen Magazine Comics, translated)

Note: Chapter count includes 2 extras.