S1E21 : The Detective Chapter - Part 6 - Conviction

Shion tricks Keiichi in a phone call and later tricks the townsfolk in order to make Keiichi a murder suspect, however she quickly realizes that Oishi suspects her instead. When discovered by Rena and Keiichi, Shion lures Keiichi away and knocks him out in front of Mion. The truth behind the sisters' fate is revealed.