Adult PC Game: Lover of Mirror Image (Jap, Eng) by Ishigaki Archive

This game is a side scrolling action game where the main characters are twin incubus / succubus by the names of Tohno and Ano.
There are 6 stages in total.

Controls:
[←] [→]: move
[↑] or [D] or [Button 7]: Jump
[↓] or [C] or [Button 3]: hide
[Z] or [Button 1]: attack / decision
[X] or [Button 2]: Cancel
[A] or [Button 5]: Its Special Move
[S] or [Button 6]: physical strength recovery
[Space]: Pause
[Alt] + [Enter]: Full screen switching