TOKYO — In the men’s marathon, it takes bravado to aim for a spot on the Olympic medals podium higher than runners from Ethiopia and Kenya, who have dominated the sport for years.

But Arata Fujiwara, Japan’s top marathoner, has made a name for himself by bucking conventional wisdom. In a country that values predictability, hierarchy and modesty, he does not belong to a running club, coaches himself and has a unique training regimen that emphasizes speed over endurance.

Shunning the teams that compete in the corporate distance relay, or ekiden, which dominates Japan’s running world, Fujiwara is a provocative figure who has befuddled supporters and skeptics alike. To some, he represents a new breed of runner willing to try new methods and expand beyond Japan’s insular running world, which discourages racing overseas. To others, he is challenging the existing order tilted in favor of Japanese television broadcasters and team sponsors.

His performances have been just as bewildering. Fujiwara has finished second in the Tokyo Marathon three times, including this year, when he ran 2 hours 7 minutes 48 seconds, the seventh-fastest time for a Japanese man. But he has also run slower than 2:20 in other marathons, including several overseas.