Toushi was along when one of Genius' memories were shown. Apparently, Genius had a job where he erased people's memories.

[sighs, tapping her fingers against the mug]

Toushi didn't take it well, and punched him in the face. They feuded for a while after that, and while I can't say one side acted better than the other, I will say that Genius' friends ganged up to yell at Toushi whenever they saw the chance. And he couldn't understand how they could be mad at him for punching Genius, when in his mind, Genius' actions had been so much worse...so of course that just made him more defensive.

But they were worried that Genius would be in danger if people found out what he used to do...or if the powers that be concluded that he could reverse everyone's memory loss.