Shibuya Kazuya is the 17 year old president of SPR. He is sharp and extremely intelligent, but very much a narcissist...so he has been nicknamed by Mai "Naru" (Short for narcissist). Contrary to the other characters, he does not appear to possess any kind of spiritual power, and must count on his companions' abilities and his own intellect and knowledge to solve the cases they investigate.

Though appearing cold and critical in front of his friends, he does care for them deeply and has earned their trust and respect. He and Mai apparently share a close relationship as she is the only girl he addresses by given name, unlike Masako, who becomes jealous of Mai as a result.

(Source: Wikipedia)

Major spoiler: