Mahou Shoujo Lyiene -Inma no Shirenjou- by Luna Soft - Adult Sex Game

There is a dungeon located on a small island called "Vanaheim".
This dungeon is rumoured to be the location where the legendary Witch "Alice" bequeathed a legacy upon her death, because of this many adventurers have travelled to this dungeon seeking Alice's Legacy.
However, the dungeon is infested with dangerous monsters and traps, to this day not a single adventurer has laid eyes on the Legacy.
The Mahou Shoujo (Magical Girl) Lyiene is another who has come to the island having heard the rumours about Vanaheim island.
The adventure of Mahou Shoujo Lyiene, who seeks to uncover the truth of the legendary witch's legacy which sleeps within the dungeon, begins now.