Wiki says :

According to reports first published in Japanese newspapers, he went to school in Switzerland near Bern. First reports claimed he attended the private English-language International School in Gümligen under the name "Chol-pak" or "Pak-chol" from 1993 to 1998.[22] He was described as shy, a good student who got along well with his classmates and was a basketball fan.[23] He was chaperoned by an older student, who was thought to be his bodyguard.[24]