Yankee-kun ga Nakasareru Wake

Naruse, a strong delinquent, admires his first love, Kuga, who saved him from bullies when he was a child. Six years later, he enrolled into the same school as Kuga, but when they met again, Kuga had become a shadow of his former self. Naruse believes that he's still the Kuga he fell in love with, so he's determined to confess his feelings before graduation. He tries to approach Kuga in order to gain his favor, but for some reason, Kuga mistakes him as a bully... (Source: East Press, translated)