Hajime wasn't sure what it was, exactly. It could be a product of anxiety or just Tsukishima’s natural state, because once you get the boy comfortable, he rocks. Sometimes it was small: a swaying head, a bouncing leg. Today, though, it was everything.
They were supposed to be studying and Hajime had half a mind to feel guilty for not focusing on Japanese grammar rules, but Tsukishima was rocking. His grey chew necklace sat in his mouth, motionless and his glasses were on the table and his entire torso was moving back and forth. His brown eyes were still tracking across the text of his notebook though, so clearly this was a subconscious movement, similar to how he would occasionally naw on the necklace in his mouth.
Hajime didn't know what to do.
On one hand, wasn't rocking a sign of anxiety? It always was for Tooru. But on the other hand, this kind of languid rocking, the rocking that Hajime had only seen once or twice before, seemed so much more relaxed. Like this was how Tsukishima prefered to exist. How much energy does he spend trying to stay still then?
Hajime always knew Tsukishima was tedious in how he presented himself to others, so really, this shouldn't be much of a surprise. His mouth curled up into a smile, happy that Tsukishima was comfortable enough in his small, messy apartment to let himself exist.
As soon as the smile appeared, though, the rocking stopped and Tsukishima glanced up at him quizzically, pulling his necklace out of his mouth. “This shit isn't making enough sense for you to be smiling,” he snapped, glowering at the books spread around them at the table.
Hajime’s smile turned into something more self-conscious. “Ah, sorry, sorry. I was going to ask a question, but got distracted. I'm still not used to seeing you without your glasses,” he said easily. It wasn't exactly a lie.
Tsukishima’s face twisted in confused irritation. “So you decided to smile at my face?”
Hajime shrugged, avoiding his eyes. “Didn't realize I was smiling.”
Tsukishima clicked his tongue. “Stop thinking sappy shit. We got test tomorrow.”
Hajime froze, staring at the books around them in mounting horror. “Tomorrow? Didn't the professor say it was on Thursday?” Hajime’s voice definitely didn't crack. He definitely didn't want to cry. He definitely didn't wish that he could remember prefixes as easily as he could remember Tsukishima's stupid habits that distracted him from the prefixes in the first place.
Tsukishima whapped him on the back of his head with a notebook, snapping him out of his reverie. “Tomorrow is Thursday, idiot. Stop gawking and start studying.”
Hajime grunted in acknowledgement as he scrambled to find his place in the textbook. “Didn't... have to hit me though.” His words came out a bit delayed, distracted by his attempt to make up for lost time.
“And you didn't have to stare at me for five minutes straight,” Tsukishima countered easily, scribbling something down in the margins. He had started rocking again. Hajime wondered if it helped his concentration.
Well, it certainly doesn't help yours.
“Dunno if there was anything straight about me staring at you.” Did Hajime actually say that? Whoops. Tooru would be proud.
Tsukishima's pen froze. Tsukishima froze. Hajime aggressively attempted to look absorbed in his studies. And then Tsukishima laughed. Not his I Hate You laugh or his I Tolerate You laugh, but his Yamaguchi Tadashi Made A Joke laugh. Hajime was somewhat aware that he had turned to stare with the same, sappy smile while Tsukishima’s pen tumbled from his fingers and his eyes crinkled shut and he bent forward and covered his mouth and he laughed.
“You sound like Tooru!” he managed to gasp out as his laughter began to fade.
Hajime grinned. “If it makes you laugh like that, I'll start quoting Tooru more often.”
Tsukishima's face straightened into something that screamed oh god, no, but Hajime had already opened his mouth.
“Megane-chan, don't be so grumpy!” he chirped in his best Obnoxious Tooru voice.
Tsukishima’s face was the very picture if dread, but there were traces of amusement in his eyes.
“Megane-chan, jealousy doesn't suit you!” Hajime sang, a broad grin on his face. He was about to continue when-
“Iwa-chan, you brute!” Tsukishima cried, a perfect imitation of Tooru, with the most deadpan face he had ever mustered. Hajime laughed sharply in surprise.
“What the fuck , Tsukishima, your face..!” he choked out.
“I’ve been practicing,” he said conversationally, smirking at Hajime’s amusement.
And Hajime only cackled harder at the mental image of Tsukishima practicing Tooru voices in the mirror in his spare time.
“Jesus, ‘Zumi, it wasn't that funny,” he chuckled as tears began forming in Hajime’s closed eyes.
“Y-you actually… practiced…” Hajime struggled to form a full sentence around his laugh.
“My therapist recommended it as exposure therapy,” Tsukishima answered gravely.
Hajime fell off his chair.