Kaitou Tenshi Twin Angel: Maboroshi no Shoujo

A freeware visual novel spin-off belonging to the Twin Angel franchise. The story follows life-long friends and classmates Haruka Minazuki and Aoi Kannazuki at St. Cherine Academy. While they appear to be ordinary students by day, they secretly transform at night into the heroic, magical "Phantom Thief Angels" to fight evil and thwart major conspiracies.