Ken Ma Ryou Joku

Our hero Itsuki is the most average joe you could ever expect to meet. On the last train of the night, he dozes off. When he wakes up, he finds himself in a mysterious forest he has never seen before.
As Itsuki wanders about the forest looking for a way out, he stumbles on a lady warrior who has been trapped by a slime monster. Evidently, this is not present day. This is a world of fantasy and heroism like the ones you get in games or anime!
Many women have been captured by orcs, goblins and even fairies, becoming their playthings. Can Itsuki save them all?

[from DLsite English]