Hikaru had nature talent in Go. He could remember the position of the Go-stone simply by looking at them. In Chapter 43, he impressed Kaga that he was able to remember all 3 positions of the game he just played easily.

Hikaru's skill grew up in tremendous speed, yet he is still so ignorance about many things.... In chapter 105, Hikaru shocked everyone by mistaking Oteai as some "BIG" competition. Oteai is actually match that will decide Pro's Dan Level.

And, he had horrible handwritings ^^;;; Very artistic, isn't it?