Hero gets to the island where a witch lives. First location - mansion with a few NPC who sell you stuff (nurse, blacksmith, maid? and witch). Island is full of mosntergirls, who you can take to the dungeon after defeating them and train on them (the more you defeat them in dungeon the weaker they get and after a few defeats they stop attacking and lose automatically after a few turns in battle). Same goes to bosses. After collecting all bosses there was a special harem scene in dungeon. In the end MC tries to leave the island and witch confronts him, turns into younger self and fights with MC. And to get the best ending you had to collect all mosntergirls and defeat them in dungeon into the weakest state. And there was a problem that some people couldn't get angel girl to the weakest state and get the ending.