Tentacle Master ~Kyou Yoku no Shihaisha Sebun~

In an underground world, a charismatic tentacle master known by the codename "Seven" for his achievement of reaching the highest rank of tentacle master works in Tentacle City. As a tentacle master he must control the tentacle monsters, who are no more than sex craving beasts who can think of nothing but sex With the power to control them, he uses them to train women.

Sick of dealing with training low level women, Seven takes a vacation. But then one day, he gets an unexpected request to train someone with a level 7 resistance to tentacles named Elise. Elise happens to be the daughter of the famous Sheerfield iron lord. Seven's tentacle master heart is set ablaze with happiness by getting exactly the kind of test material he's been looking for!!

Your goal is to become seven and train Elise to be a great female slave within a short amount of time. Turn her into a female sex slave while controlling tentacles and not bringing shame to the name of the great tentacle master.

[From DLsite English]