Kochōkai was founded in 2011 by Arjan F. Tervoort. Arjan stepped into a dōjō to learn judō when he was eight years old. And since that time he has always studied budō.

After a few years an interest began to form for weapon-arts and Arjan has trained in ninpō bujutsu, a “spin-off” modern school in the Netherlands based on the teachings of Takamatsu Toshitsugu, for about 11 years.

During this time, Arjan started to practice meditation, and at age 16 he started the practice of zazen in the Sōtō/Rinzai-line of Maezumi Taizan. Today Arjan practices Zen with Andre van der Braak at the Zen center in Amsterdam.

Besides ninpō Arjan practiced other budō forms. One of them was aikido, in which Arjan has been training from 1999. Starting with Gertjan van Dijk, then for a long time with Erik Louw, Simon Deering and currently in Aikidojo-Haarlem with Martijn Duchatteau of Yuwakai, where he received shōdan in 2011. Since the start of his aikidō training at Aikidojo-Haarlem Arjan has been teaching classic weapon class on Friday-evening there.

From his aikidō teacher Erik Louw, with whom Arjan is studying since 2002, he learns the classical weapon school of Tenshin Shōden Katori Shintō ryū. In the beginning Arjan learns both the main line of Otake Risuke as the lines of Sugino Yoshio and Hatakeyama Goro. Before Hatakeyama sensei’s passing Arjan receives mokuroku from him.

Since 2010 Arjan practices Mugai ryū iaihyōdō, and receives sandan from Niina Toyoaki soke in 2013. Arjan teaches Mugai ryū in Kochōkai Haarlem. That year he also started his practice in chadō (tea ceremony) with Herman Somsen of the Urasenke school.

In 2012 Arjan started his training in Meifu Shinkage ryū shurikenjutsu and Jiki Shinkage ryū naginatajutsu (schools whose names happen to be similar / there is no links between the two schools) and he restarted his practice in kyūdō (he initially started in 2005 but discontinued his practice after a few years).

From 2014 Arjan has been training Hzōin ryū sōjutsu in a study group at Kochōkai. He also coordinates the biannual “European Kobudō Convention” since that year.

Arjan speaks Japanese and has visited Japan several times for training and cultural studies.