Vanish!

The full title of this game translates to "Vanish! ~Kingdom of Disappeared Boobs~". The subtitle refers to the fact that all females in the Roshtoll Kingdom have child-like body proportions, although it's unclear if it has anything to do with the plot of the game.

Story Background
Kurosu Kensou (黒須賢三) was studying abroad at the Roshutoll Kingdom, famous for its magic. With his excellent grades attracted jealousy, and during the well-publicized Entrance Ceremony of the Mage Academy, he was tricked into announcing his dream of using magic to do H stuff. As a result, he became despised by all the females in the kingdom, and no mage would accept him as apprentice. His H ambition was about to be thwarted.

Then, Princess Rene referred to Kensou a legendary witch, Kororoko Swallow, who got her magic sealed due to all the bad things she had done, and who just might be willing to accept Kensou as an apprentice.

How did the princess of the kingdom become associated with an infamous witch? Feeling uneasy, Kurosu Kensou sought out the forest where the witch lives in order to fulfill his H dream.