Kai

Tenshi ni Narumon, 1 layer, A2, 1 sketch, no background, TV

Kai is Natsumi’s boyfriend at the beginning of the series.  He was formerly her deceased older brother Fuyuki’s best friend and classmate.

Kai only shows up a few times in the first half of the series, but a conversation he has with Natsume plus one later with Yuusuke reveals her struggles over dealing with the loss of her brother.