A creature of habit
Saruhiko Fushimi for all he hates to admit it is a creature of habit just like every other human being. He is easily annoyed and when he gets like that there are a few ticks that tend to show.
Whenever Saruhiko runs across, or even thinks Yata Misaki he ends up scratching the half healed scar he created in an effort to hurt Misaki by burning through his Homra scar. He initially figures that one day he may grow used to it.
Saruhiko will often click his tongue when confronted with someone whose intelligence he believes to be subpar. In is one of the things his subordinates and enemies note most about him. He will often avoid conversation with those he thinks less of in order to respond solely with the clicking of his tongue.
"He always answers everything with the click of his tongue." - Fuse Daiki, Days of Blue Ch. 1, Pg. 17
Saruhiko taunts his rivals often by attempting to throw them off their game. When they accuse him of something (such as being a traitor) he will respond by agreeing to it or reminding them of their accusation when he is winning.
Saruhiko doesn't eat or sleep on a regular schedule. He often forgets to eat and drink entirely. When he does finally settle down with food it is often limited to energy drinks and protein bars. When he lived with Yata Misaki he often relied on Misaki to cook for him. Misaki dealt with Fushimi's picky eating habits and refusal to eat anything resembling vegetables by putting things like Pineapples in hotpots and acquiescing to his request for "mild grape juice with zero percent fruit. Even better if it's semi-carbonated".
Saruhiko has failed to get over the loss of his friendship with Yata. He continues to sleep in the top bunk at Scepter 4 HQ because that's where he slept when he lived with Yata. He occasionally looks for Yata when fighting alone.