Doumo, Yuusha no Chichi desu. Kono Tabi wa Gusoku ga Gomeiwaku wo Kakete, Moushiwake Arimasen.

Croix, who works as a lumberjack in a remote village, spends peaceful days with his beautiful wife, Wiel, and his only son, Alka. One day, Alka receives an oracle that he is the only one who can defeat the Demon King, the "Hero," and together with his fiancé Saya, he sets out on a journey to subjugate the Demon King... However, one day, three years after receiving the oracle, Saya returned to the village in tatters. From Saya's mouth, Alka is flickering his authority as a hero, and is told that he does whatever he pleases without saving the world... to wake up his stupid son. Hit him with your strongest fist!!

(Source: Futabasha, translated)