A man was arrested in Japan for sending a threatening letter to Princess Kako of Akishino. 

Motohiro Yokouchi, a three-year-employee of a company in Kyoto, admitted that in June, he had sent an envelope to the International Christian University—in capital city Tokyo—, where the 20-year-old princess studies. 

In Yokouchi’s words, thus he wanted to teach a lesson to his former subordinate, and placed his business card inside the envelope, reported Lenta.ru, a Moscow-based online newspaper in Russian.

Princess Kako, a granddaughter of Emperor Akihito, had entered the university in April.