|Affiliation||Knights of the Eastern Calculus|
|Voice Actor(s)||Rachael Harris (English),
Eriko Kawasaki (Japanese)
Masatsugu Shoko was a member of the Knights of the Eastern Calculus. She was the mother of Shou Masatsugu. A mysterious PCB assembly is delivered to her in Layer 07. She committed suicide when her identity was exposed in Layer 10. She was presumably restored to life when Lain deleted herself from physical existence in Layer 13. According to Visual Experiments Lain, her Wired handle is maruneko (まるねこ).