Mika accepts there are some genius born once in hundred years but they still need time to get use of their intelligence, to gather all kind of knowledge. Usami's achievements are really grand, it's not like he has started experimenting since the moment he was born nor does it explains the no. of human experiments he did, he also may have done many experiments on animals too, thus Mika's theory of Usami not being a normal human makes more sense then Usami's age, in the view at least.
And how can he forget the reaction of the spirits at the the haunted house upon Usami's arrival, he must be either immortal exorcist or a devil.
"I am neither immortal exorcist nor a deivl, now hurry up with your food and go to bed." said Usami done with his supper.
'And this telepathy ability.' thought Mika.
"No one needs telepathy to know what you are thinking of." Usami replied to Mika's thought and went to lab.
