Unlikely Ordinary

Arthur Morgan is just an ordinary student or is he? He have basics skills and average intelligence but is it his all?
He just want to live ordinary. People criticize him for being ordinary.
Until he met a girl. But who is she?
This has forced Arthur to slowly adapt and show his true skills. Taking actions slowly to have a high chance of winning.
Taking a look at his past is a dark and narrow path. A feared and already genius. Genius or beyond genius?