Isekai de Cheat Skill wo Te ni Shita Ore wa, Genjitsu Sekai wo mo Musou Suru ~Level Up wa Jinsei wo Kaeta~ - Vol. 3 Ch. 14 - Temptation Of The Bath

[MangaDex]

 

[Otherworlder]

Lessee... cute-but-powerful mascot, OP without effort, "As expected" (from the princess), harem, and now an onsen. Bingo! I got bingo!

I like how the dog is not only more than twice the MC's level, but is nearly twice as intelligent, as well.