Hebi no Cinderella

Saki Kiyuki is a plain, frugal 30-year old cleaning lady who has given up on any hopes and dreams she held on to once.
Her life turns around after an incident where she ends up standing up for a salaryman who was falsely accused of molesting another passenger during her morning commute. The man, Rei Sannomiya, befriends Saki and slowly she regains some optimism in her future.

They meet, grow closer, fall in love... And then...
A modern-day suspense problematic yandere villain visual novel.

[Translated from DLsite]