The Assasin

The Assassin (Real name unrevealed) is one of Friend's assistants. He is the one who pushed Moroboshi, Kiriko's beloved one, in front of a train and caused his death to let the first Friend (Fukubei) be with her. He also lured Dr. Shikishima's daughter into being his girlfriend and to be under Friend's command, so that Dr. Shikishima would create the first Robot for him.