If you had no idea who this was... then you are SO ZETTA SLOW.
Sho Minamimoto is a villain in Subarashiki Kono Sekai, an all around batshit-insane math geek and the main bad guy who takes on the appearance of a Rap Gangster.
Famous for both copious use of math-related puns and the use of the word "Zetta" every single time he speaks, "So Zetta Slow!" being the highlight.
This tag has been aliased to minamimoto_shou (learn more).