Koki, 23, was a full-time racer in the Japan Grand Prix, and has made multiple appearances as a wildcard on the world stage.
Koki was on his way home from a charity event, where he was helping to raise money for the many earthquake victims in Japan, when the accident occurred.
Yuki said that he intends to race this weekend in Estoril to honor his brother.
All About Bikes sends its condolences to the Takahashi family.
Courtesy of AllAboutBikes.com