Kentaro Nara
Nara is in Tenma’s class, but goes unnoticed most of the time. He is in love with Tenma, and unlike Harima, is able to talk to Tenma easily. Of course, Harima seems to always get in his way.
He is scrawny, especially when compared to Harima, which is why he tends to always back down when Harima is around.
Curiously, according to the mangaka, his original intentions were to have Nara as the series’ main character, but somehow he was relegated to a supporting role.