Pi (パイ, Pai) is a character in .hack//Link.
Pi is a female avatar with a pair of small glasses, long pink hair and a red leather outfit that travels down her legs. Her appearance in LINK carry numerous minor alterations to her design. Most notable are her pigtails, which are much larger, and not only are completely loose as opposed to being tied at the tips, but the tips themselves transition from pink to blond. Her small necktie is replaced with a red bow tie. The wave symbols on her body are missing as well. Some other alterations are found in her hair decorations.
Reiko Saeki (佐伯令子) is woman residing in Tokyo. During 2016, she suddenly quit her job as a programmer to work at CC Corp. She is the person behind Pi, Ender and is the younger sister of lead programmer and A.I. psychologist Jun Bansyoya. After the restart of Project G.U. Pi began working for Genius to protect Yata from changes within the Akashic Records.