Sakubo is a user played by two people, Sakubo Saku is twin girl and Sakubo Bo is the twin boy.
Saku is the stronger one; speaking in harsh language and ready for any fight.
Bo being an alternate personality of Saku, is the quiet and shy one.
Saku is obsessed with Endrance; a user and also an epitaph user.
Only one of them can be logged in at the same time; being they share the same user. Although both control their avatar; Gorre.