A "shred guitar" lesson given by Fumiyoshi Kamo in April 2011 was the world's largest, attracting 8,776 "students" who viewed the online performance, according to the website of Guinness World Records.

On April 2, Kamo, 37, gave a lesson on shred guitar — a genre to which he has devoted his life — on the video-sharing website Nico Nico Live. The performance broke the previous record of 4,455 participants held by his favorite American guitarist, Steve Vai, whose success served as Kamo's inspiration for learning guitar at the age of 19.

Kamo, who spent time in disaster-hit Fukushima Prefecture as a junior high school student, said he wanted to do something positive to cheer up old friends caught up in the catastrophe last March.

He donated his performance fee for the program to the Japanese Red Cross Society.

"Rather than attaining fame with the guitar, I want to serve society," said Kamo, who is also a music producer. "It was more significant for me that I was able to devote my love to Fukushima than setting a record."