IKO Kyokushinkaikan founder Sosai Masutatsu Oyama's 23rd memorial service was held at the Mt.Mitsumine Shrine in the Saitama Pref. on Monday, April 17, the day after the 2017 International Karate Friendship and 6th World Weight Category Championships. Approximately 270 members took part in this memorial service which included IKO President Kancho Shokei Matsui, Shihan Yuzo Goda, Shihan Peter Chong, Shihan Seiji Isobe, Shihan Kenny Uytenbogaardt, Shihan Katsuhito Gorai, Shihan Stuart Corrigal, Shihan Francisco Filho, IKO officials, Branch Chiefs from all over Japan and overseas, fighters who participated in the IFT, 6th WWC, International Training Camp participants and headquarter staff. Participants together gave prayers to the founder of Kyokushin karate. The memorial sevice started with a prayer Shinto style then members moved to the "Soreisha" where Sosai Oyama's spirit rest and finished by paying respect to Sosai's Monument.
After lunch Kancho Matsui lead the 2hr 30 min training session mainly focusing on Kihon and Ido followed by the Dan Test with 40 members from brown belt to 4th Dan participating. The next day Shihan Filho led the early morning training and there was the Kumite test for Dan Test participants.