The song was first uploaded on April 29, 2008. As the title goes, the lyrics of the song are the first 1000 digits of Pi (which is said to be infinite). It's also the song which made ΠP's P name. It's available in JOYSOUND, and also, it was hinted that Len was the first to "challenge" Rin in the 1000 digits of pi challenge. Later on, the succeeding versions goes to 1,200, 2,500, to 10,000 digits.