Akiharu Usami (宇佐美 秋春, Usami Akiharu) was a student of Rokumeikan University and a friend of Mikoko Aoii.
Akiharu was a seemingly carefree guy. He had a habit of forcing his opinions down other people's throats, a fact that cause Muimi Atemiya to scold him a lot.
He foresaw his death and, although there is no way to confirm this, I likes to think that Akiharu figured out the mystery before anyone else and accepted his death at the hands of his friend. If true, that would show that he was the most loyal friend of the bunch, as he accepted his friends the way they were.
He was so forgettable to him that I couldn't remember his face a few days after he met him. After the Strangulation Incident wrapped up, I forgot about his existence completely.
Although his appearance is never shown, Akiharu is described as being a normal-looking guy wearing urban fashion.