Didn't enjoy this at all, sorry. The navigation was horrible, even with the fast travel options. At one point, the MC says to find a girl on a rooftop that doesn't even exist in the game. Then, the guide in the phone for events says to do things, but those 'events' are just dialogue? Kept 'interacting' with Hayami to get her stats up and then next I know the events list says she has none. So, that was it? Them discussing classwork and astronomy and math? That's the game's depiction of an 'event' in an AVN? Never seen an AVN use 'event' for anything outside of an H-scene before.
Also, how is this high school? There is only one class you attend, and you choose whether to go or not? That sounds like college, where you show up two or three times a week for an hour or two and that is it.
As for characters, I never felt any of them had personality. They all felt very bland and generic. Outside of physical appearance, they felt similar and unforgettable, sorry. For example, Hayami speaks to and treats the MC very much the same way as Haru. Maybe that all changes, but I gave up on dawn of day 6.