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. In 2014 he received his dharma-naam Fusō 不争 (no conflict) from his teacher André van der Braak (Zen teacher and professor Buddhist philosophy at the VU Amsterdam).
Arjan has 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 nidan in 2014.
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 Godan and Okuiri from Niina Toyoaki soke in 2019 and is also made Shidoin. Arjan teaches Mugai ryū in Kochōkai Haarlem.
In 2010 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 Hōzōin ryū sōjutsu in a study group at Kochōkai. He also coordinates the biannual “European Kobudō Convention” since that year.
| Started in | Current grade | |
| Aikidō | 1999 | Nidan (2nd dan) in 2014 |
| Zazen | 1999 | geen graad: Jukai in 2014 |
| Tenshin Shōden Katori Shintō ryū | 2002 | Nyūmon Otake dōjō 2005 Mokuroku Hatakeyama dōjō in 2009 |
| Kyudō | 2005 | Ikkyu 2014 |
| Mugai ryū | 2010 | Kaicho in 2011 Yondan (4th dan) in 2014 |
| Meifu Shinkage ryū | 2012 | Branch leader in 2014 Nidan (2nd dan) in 2014 |
| Jiki Shinkage ryū | 2012 | – |
| Chadō | 2012 | – |
| EKC | 2012 | Director in 2014 en host in 2015 and 2018 |
| Hōzōin ryū Takada-ha | 2014 | – |
