Helck

Cleo is a mercenary whose dream is to buy his own home and live peacefully. But while he’s fleeing from a group of bandits that were unexpectedly strong, he meets a mysterious demi-human girl named Kohaku that claims to have foreseen his death. And for some untold reason, she has also vowed to protect him from any and all danger. Will Cleo manage to survive and live his dream life? 

(Source: Comikey)

Its figure was as divine as the phoenix of legends, and the timbre of its songs was more majestic than any instrument. It's said that if you were to encounter it, you will be promised happiness...