Identify Male MC and female best friend go back in time

annofrog

Newbie
Jul 24, 2017
27
26
I'm looking for a game I downloaded here about a year ago.
IIRC it started with the MC at school, he goes back home with his female best friend, the best friend had a crush on MC's sister.
At some point they go take some pictures of animals for a school assignment and end up finding a magical thing, after researching about it in a library they touch it and travel in time.
In the past they found the MC's mother and the MC's best friend have sex with her, the MC get pissed about it.
I vaguely remember a water tower they climb, and something about a coat the best friend lost

I remember that there was a map, you could move around between locations, so it wasn't linear.
It was 3dcg and had good renderers.