Adult PC Game: The lethargic angel is missing credits in the Department of Sexual Activity Ver.1.93mod1 by Nakayoshi Honpo Archive

Service subject...It is one of the most important subjects for apprentice angels who will one day help and guide humans.
However, Mika, a lazy and lethargic apprentice angel, is in danger of repeating a grade because she skips classes too much!
If this continues like this, he will remain an apprentice angel forever...!?
In order to overcome this situation, he descends on the human city with fellow angel apprentices Bel and Az, as ordered by the goddess Freya.
However, what awaited them was the sticky and glistening sexual desire of men...?