Fumikage has a reserved, serious and focused personality. Though he does not talk very much, he has been shown directly ignoring questions or requests that seem in some way pointless (like Tenya asking him to not sit on the desk) while he talks to other people as some sort of ongoing joke. When Fumikage teams up with others, he becomes more sociable, helping his teammates out, reassuring his trust in them and thanking them for their effort.

He appears to be fond of darkness and other related concepts, sometimes coming off as a slightly dramatic, having a tendency to say dramatic things about situations that don't quite deserve them, such as calling a recreational game on their school trip a "mad banquet of darkness". Despite this, he is also shown to be embarrassed about his interests to a certain degree, refusing to let his classmates see his gloomy room. Fumikage also seems to have a certain level of belief in the concept of fate and destiny.