Memesis (Yagyuu Takuya)

Memesis (Yagyuu Takuya) manga summary: In a fantasy world where monsters roam the land, the heroes party of Leon, Kijira and Ash traveled and slayed monsters together. But when Leon broke up with his partners so he could hang out with cute girls, Kijira and Ash starts carving their own legacy and it's one built on the back of jealousy as they look to overcome Leon in both monster slaying and women wooing.