Midori Days (anilist-30572)

Seiji Sawamura is the toughest seventeen-year-old in town, feared by all for his fighting prowess and his deadly "Devil's Right Hand." But at heart, Seiji is a softy, and all he wants is an end to his seventeen-year history of being a lonely single guy. Unfortunately, his tough-guy reputation only serves to decrease his popularity with the ladies, until one day he wakes up to find a girl named Midori has replaced his right hand, and admits she has had a crush on him since middle school.