how many ending are there?
There's a spicy/NSFW ending, a good/normal ending, and a bad ending (called "dead ends") for each day!!
Some endings can also be achieved in various ways, such as choosing to invite Ren over (or declining him) in Day 1, choosing whose apartment to visit in Day 2, or calling various people in Day 3! They all offer a good ending, but will have unique and different outcomes.