Mahou no Shoujo Silky Lip ~Sannin no Joou Kouho~

Lip is an unskilled magic girl. One day, she is nominated for the next Queen. Though she doesn't know what's going on, she is ordered to stay in the human world for one year as training. Surrounded by various people, what will she learn? How will she grow up...? ----- Twelve years later, the Queen finally passes away. At the same time, the Magic Crystals, sealed by the Queen's power, explode and scatter around the human world. The King tells Lip to collect the Magic Crystals....

[From ErogeShop]

Additionally, this game is based on Mahou Shoujo Silky Lip, a Sega CD game. The first part of the story is a remake that reproduces as much of the canceled PC Engine version as possible and incorporates episodes and messages from the Sega CD version while the second is a new 18+ sequel story.