If It's for My Daughter, I'd Even Defeat a Demon Lord

Uchi no Ko no Tame Naraba, Ore wa Moshikashitara Maou mo Taoseru Kamo Shirenai.
うちの娘の為ならば、俺はもしかしたら魔王も倒せるかもしれない。

Source

If It’s for My Daughter, I’d Even Defeat a Demon Lord
Uchi no Ko no Tame Naraba, Ore wa Moshikashitara Maou mo Taoseru Kamo Shirenai.· うちの娘の為ならば、俺はもしかしたら魔王も倒せるかもしれない。
novel

Dale is a cool, composed, and highly skilled adventurer who’s made quite a name for himself despite his youth. One day on a job deep in the forest, he comes across a little devil girl who’s almost wasted away. Unable to just leave her there to die, Dale takes her home and becomes her adoptive father. Devil or not, Latina is beyond adorable, and the adventurer soon finds himself head over heels with being a parent. But why was she out in the forest to begin with, and why does she carry the mark of a criminal? (Source: J-Novel Club)

Side Story

Uchi no Ko no Tame Naraba, Ore wa Moshikashitara Maou mo Taoseru Kamo Shirenai. Bangai-hen 6: Osanai Shoujo, Aru Tabi no Hi no Asa.
うちの娘の為ならば、俺はもしかしたら魔王も倒せるかもしれない。 番外編6 幼い少女、ある旅の日の朝。
manga

The 6th and last side story which never got included in the final volume of the manga.