Higurashi: When They Cry: Season 1, Episode 4

1 - 4: The Hidden Demon Chapter - Part 4 - Distortion

Keiichi's despair reaches its peak. After being captured and sedated, he wakes up restrained by Mion and Rena, and they attempt to inject him with a mysterious drug. Keiichi murders them before taking his own life by clawing his throat.