Okay this might not be what it's called, but I'm calling it the "Library Club" anime. It's based on a popular adult PC game called Daitoshokan no Hitsujikai: A Good Librarian Like a Good Shepherd which is not only extremely long, but kind of nonsensical. The librarian part refers to the club that acts as the setting for the story and the shepherd refers to a character in the story that acts as the catalyst... but you have to know the story to get any of that so it's just weird to me.
The story revolves around the main protagonist Kyotaro Kakei, who is the sole member of the Library Club at Shiomi Academy. One day he receives an email from the "shepherd" (hitsujikai) who is said to be able to fulfill any wishes. It says, "You will experience a life-changing event today." After an encounter with a second-year student Tsugumi Shirasaki on the day, more and more cute girls join the club to be with him.