Hawaii was the popular origin of surfing and the most popular water sport. Oscar van der Kirk and Charlie Kaapu were avid surfers, and taught tourists how to surf. Waikiki's beach was the popular site of surfing. During and after the Japaneseinvasion of Hawaii, Japanese soldiers and military personnel were unfamiliar with surfing, as it was nonnative and unheard of in their country, and were simply amaze by it. During the invasion Corporal Takeo Shimizu and Lieutenant Osami Yonehara first saw surfers Oscar van der Kirk and Charlie Kaapu, who were surfing. Shimizu consider them to be kami (spirits) and Yonehara even compared them to Jesus Christ walking on water.