Yokoo and Satou/Relationships

Minamoto Kou
They were sorted into the same class upon entering Kamome Academy's middle school. They've been close friends ever since. Yokoo and Satou are often shown standing near Kou and Kou would get worried when Yokoo and Satou get affected by some supernatural.

Mitsuba Sousuke
They were sorted into the same class upon entering Kamome Academy's middle school. It was implied they were on friendly terms, but because of Mitsuba faking his personality, they had drifted apart. In Number 4's imaginary world, it appears Yokoo and Satou would have gotten along well with Mitsuba, had he shown his true personality. In this world, they are close friends with Mitsuba. Yokoo is also shown to remember Mitsuba, reminding Kou who he was.