Akira Haraguchi (原口 證, Haraguchi Akira) (born 1946, Miyagi Prefecture), is a retired Japanese engineer known for memorizing and reciting digits of pi.
Haraguchi holds the current unofficial world record for reciting 100,000 digits of pi in 16 hours, starting at 9:00 a.m. (16:28 GMT) on October 3, 2006.
The event was filmed in a public hall in Kisarazu, east of Tokyo, where he had five-minute breaks every two hours to eat onigiri to keep up his energy levels.
Haraguchi views the memorization of pi as "the religion of the universe",[3] and as an expression of his lifelong quest for eternal truth.
Haraguchi uses a system he developed, which assigns kana symbols to numbers, allowing for the memorization of pi as a collection of stories.