Zettai Sakusei! Succubus-chan

You are a boring job hopper. You have nothing to do other than part-time jobs, so you waste a large part of your lifetime fapping. But one day you make up your mind to take nofap until you find a steady job. Very nice, I think.

One of these days, a magic gate suddenly appears in your room and a bewitching and beautiful girl from another world comes through the gate. She says she will make you be reborn as an evil hero in the alternate world, and some special training is needed to do so. The training will be done by... Sex! Moreover, a variety of abnormal plays are included as mental training!

Placed before the higher-ranked succubus' sexual techniques, your soul is about to be corrupted...

[From DLsite English]