The protagonist (you) have come to a high class mansion to service the elevator.
It was supposed to be the same old maintenance job...
That was, until some lady got on the elevator with you.
Her unguarded posture, tempts you to secretly photograph her... upskirt.
What kind of panties is she wearing you think and when you take a look...
You are pleasantly surprised! "With this image, I can totally blackmail her."
Forget servicing the elevator. It's time for some maintenance work on her!

[From DLsite English]