Naruto: I'm Not a Pokémon - Chapter 4 Class

In an inaccessible village, there were a few houses on the hillside.

People from far away were attracted here and the mountain road was crowded with luxury cars, because, in this town, there was a young man with incredible medical skills who could cure all kinds of illnesses!

- Description from Novelupdates

18 years have passed since I was born as Allen, the eldest son of an earl in this world, while still retaining my memories of the present world. This world is peaceful and a stable society. The only extraordinary thing is that I was reincarnated into a world that is lenient on the existence of concubines. I selected a silver-haired maid as a sex slave and second wife candidate from among 10 candidates after a strict fellatio practical exam. I then lived an erotic life at home and at school as an attendant, but my reincarnated life is so fulfilling that I'm worried it will explode, as my busty childhood friend, a noble girl who was unsuccessful, ran for the third wife candidate, and my stepmother, who was my virgin partner, was sold off.

Ade has lived in an incense burner for over a thousand years, her days spent sleeping. Longing for the outside world she hears about from her fairy friends, her wish is finally granted when a man brings her home, releasing her from the seal. Ade, tears streaming, vows to repay her savior to the fullest extent.Qin Yu, known as the cold and ruthless Third Master Qin of Kyoto, finds his life upended when strange occurrences plague his bedroom after he places an antique incense burner given to him as a New Year's gift there. Chaos ensues, with items displaced and unexplained puddles of water; he even senses something in his bed while half-asleep.One afternoon, Qin Yu comes home early to find a young girl cleaning up spilled milk. The girl, her black hair cascading, her skin porcelain, is startled by his return and tries to flee. Upon being caught and questioned by Qin Yu, she timidly speaks of repaying her debt.To Qin Yu's amusement, she lists her belongings: pearls, antiques, even her savings. None of these interest Qin Yu, who instead sweeps her into his arms and suggests a more personal way of repaying the debt. Terrified, the girl's beautiful fish tail is revealed.

Two heroes of the game Legend of Heroes 2 who were rotten waters*.