Need help finding a story

[tinchek]

I tried the search function, tags and going through my history but with no success. So I need your help please.

So the guy is living alone or I think in his parents basement/apartment when his sister comes back from the army. She moves back in but in his space/apartment, that he now has to share. She is in the room on the other of the wall and he spies on her masturbating We later find out she put on show for him. She helps him get back in shape. The guy is also overly fond of his rain shower, where you can walk around and the shower kinda follows you.

So can anyone help me please?!

 

[Hotcappucino]

Do the siblings have sex, i.e., is it an Incest story? And I don't understand the bit about the rain shower. Is it a machine of some kind or a cloud that somehow follows him around?