昔滅びた魔王城で拾った犬は、実は伝説の魔獣でした ～隠れ最強職《羊飼い》な貴族の三男坊、いずれ、百魔獣の王となる～

The dog he found in the ruined Demon Castle was actually a legendary demon beast. The third son of a noble family with the secretly strongest job of shepherd will one day become the king of the hundred demon beasts.