Yu

Age: 17 (Chapter 1), 19 (Chapter 14), 22 (Chapter 55)
Height: 180 cm (5'11")
Reach: 185cm (6'1")
Weight: 61.1kg (135lbs), 66.7kg (147lbs), 75.6kg (160lbs)
Job: Professional Boxer
Weight Class: Lightweight -> Heavyweight

Yu is the main character of The Boxer. He is currently a professional boxer under the tutelage of the legendary K. Yu may have a mental condition called tachypsychia. Tachypsychia is a neurological condition that distorts the perception of time, usually induced by physical exertion, drug use, or a traumatic event.

(Source: The Boxer Wiki)