Wasn't Yojimbo some legendary Japanese warrior? Eh, it probably wasn't what Saori was meaning and her point was pretty clear.

"Guardian. We're called guardians." Rose shrugged. "And I technically had a choice; female guardians are very rare. The Academy basically raised me, but once I turned eighteen, I had the right to do whatever I wanted with my life. I did withdraw from the Academy for a while before deciding to go back."