found on vndb refreshing the page to find something to play just dont remember the just some general description.
student Protagonist finds people at school at night having sex and his sister is there looking lonely.
that is all that can remember.
Original Title: Vestige―刃に残るは君の面影―
Romaji: Vestige -Yaiba ni Nokoru wa Kimi no Omokage-
Release Date: 2013-10-11
Company, Producer: ALcot Honey Comb
VNDB link: https://vndb.org/r29991