The 17WKC referees seminar was held in Narita city, Chiba, Japan from June 30 to July 1^st 2018. Forty two referees had an intensive and practical training under the supervision of a chief referee, FIK shiai & shinpan director and six presiding referees. The highest temperature exceeded 30 degree in C (86 F) with no air conditioner at the gym. More than a hundred bottles of chilled water were consumed each day. All people have developed a good fellowship at the get-together party the night before the seminar, Godo geiko held for both days and the sayonara party on Sunday night. Thanks to the 20 sutudents from University of Tsukuba, Kokushikan University, Nippon Sport Science University, International Budo University and Tokai University who supported the seminar as a competitors in scorcher day. The students from Juntendo University also helped the enents with miscellaneous tasks. Special appreciation goes to Narita High School, teachers and parents who kindly the venue and supported us throughout the session. Another referee seminar will be held on September 12, two days before the championship.