Ever since you had joined Slur’s organization, Gaku had been off put. It annoyed him that Slur felt he needed someone else to do his dirty work when Gaku was capable of doing it alone.

You didn’t like Gaku either. He was too apathetic to everything, and didn’t even try to cooperate with you on missions; at least you tried to remain professional, but his snide remarks were pretty annoying, like if rage-baiting was a person, he was really good at it, his stoic face never wavering as he clearly teased you and had the nerve to act like he wasn’t.

Your constant bickering and quite literally frequent attempts to kill each other annoyed Slur to no end. His two best soldiers constantly at each other’s throats made him feel a little more like he was babysitting. Regardless, the arguing did entertain him. It was amusing to see two people with so much sexual tension in battle yet not realize it themselves. Slur had attempted to talk to Gaku about it, yet Gaku being Gaku, didn’t open up more than saying “I wanna kill her.” Yet none of that diminished the suspicion Slur had of both your attraction to each other.

Nonetheless, working with you was Gaku’s least favorite thing to do—or so he told himself. There was a thrill he got from your constant attempts at killing each other kept him on his toes, in a way that gave him goosebumps, the good kind. He wasn’t stupid, he’d admit that you were a strong, formidable opponent, and that’s what made battle with you so fun.

Yet he kept all that excitement hidden. He didn’t care enough to show emotion anyway, not like he’d ever been taught to. He was contempt enough to just have your small rivalry, as much as you could annoy him sometimes.

Like now, after your fight with Nagumo you were all beaten and bloody. Gaku had to intervene to stop you from getting killed—he knew Nagumo was out of your league when it came to fighting, you would’ve gotten yourself killed otherwise.

You were pissed at him, angry he had the nerve to scoop you up over his shoulder mid fight and take you away. You were kicking and flailing over him as he kept you grounded on his shoulder with relative ease, not phased by the fit you were having. He would’ve intervened earlier if he wasn’t so distracted by observing the chemistry you and Nagumo had, distracted by the annoyance he felt when Nagumo would flirt with you mid fight. His it pissed him off seeing you be so compatible with that happy-go-lucky prick. Gaku wasn’t able to take any more of how friendly Nagumo seemed to think he had the right to be with you.

“You can’t fight Nagumo.”

He stated, much to your offense. But Gaku knew you couldn’t take on Nagumo, and the effort Gaku had put into your rivalry would’ve amounted to nothing if you died to someone else. No one was allowed to kill you but him, you were his.