Real Name: Iori Nakanishi
Avatar: The Machinator, Gorre
Sakubo is a young girl with blond hair and a harlequin outfit. She wears a large oversized jester's hat with ornaments resembling the sun and the moon hanging from it. Depending on which player is active, the hat changes slightly. When Saku is playing the sun symbol is raised up, and while Bo plays it's exactly the opposite, with the moon symbol raised. Other notable features include the fact that while Saku is playing, her hair flairs up to give a spiked look, but while Bo is playing, his hair lays flat. Also, the "skirt" that Sakubo wears changes. While Saku is active, it opens up into a skirt, while it resembles a pair of shorts as Bo. Another difference is that Saku's backpack is red while Bo's is black. When fighting she uses a large book to cast spells, as typical of her class. Sakubo's grimoire has a sun and moon motif on each side of the cover. Coincidentally, Sakubo's Lost Weapon changes in appearance depending on who uses it. When Saku uses it the cover and back are two suns, and when Bo uses it they're two moons.
Saku is very aggressive and holds grudges. Thinking of herself before others, she'll often do things like spend money painstakingly gathered by her brother without permission. Bo is very passive and affectionate, and looks up to Haseo as kind of a big brother. The opposite of his sister, he puts others before himself.
Contrary to Sakubo's claim of being siblings, both Saku and Bo are controlled by an eleven year-old boy named Iori Nakanishi. Saku appears to be a 'big sister' personality created by Iori in order to protect him against other people, hinting that Sakubo's player may have Multiple Personalities or Dissociative Identity Disorder. Iori originally had an older sister named Sakura, but she was stillborn.
Voiced by: Megumi Toyoguchi