Alice, Clover and Zero Jr from Zero Escape: Virtue's Last Reward. Added some interim versions from photoshop cuz why not.
'm a huge fan of 999, the previous game in this series, as well as the Infinity Series made by he same creators. All of them are visual novels with dark, nonliner stories that explore concepts of time, abnormal psychology, human resonance, telepathy, and trust, and perceptions of reality. Really good stuff.
If that sounds cool and you have a DS, try out 999. As for the infinity series on PC, I'd go with Remember11.