Tomoki frequently experiences a dream involving him meeting an angel, who takes off into the sky to his disappointment. This was later revealed to be a gateway between the human world and the world of Synapse. Tomoki has shown feelings for Ikaros and Nymph and takes on the task of helping Ikaros become more human. He has also tried to break the Angeloids' tendency to obey their masters' orders completely by letting them do whatever they want, giving them a great degree of freedom to make their own individual decisions. While he constantly laments that his idealistic world of peace and quiet is ruined by the appearances of the Angeloids, he admits that he does see them as family and enjoys their company. A running gag in the series is that most of the main characters usually gather in his house for seemingly no reason other than for fun.
On rare occasions, he transforms to a female alter-ego called Tomoko through a quantum converter made by Synapse, and mainly uses this new form to blend in with the other girls so he can peep on them unnoticed. However, if Tomoki becomes sexually stimulated for too long while as Tomoko (or any other object), the transformation will end and the converter will short out. A small note is while all of the other characters are drawn in their original parameters, Tomoki is mostly drawn in super deformed parameters, with the only times being drawn in his original parameters is when he is serious or feels relaxed.
Voiced by: Soichiro Hoshi (Tomoki), Saki Fujita (Tomoko) (Japanese), Greg Ayres (Tomoki) (English)