Kagerou Usui

The actual class president of 2-He, who is ignored to the point of vanishing into thin air; only when his baldness is exposed does he become visible to others. In the anime, he has a major crush on Abiru, but leers after most female students (especially Kaere), who naturally do not notice he is there.

His name is a pun on the phrase kage ga usui ("overshadowed"), referring to his lack of presence. (The usui also refers to his thinning hairline.)