Okay yes that's smart he'll follow Nanami.

The security footage has no sound, but even so it's clear the three boys are talking loudly over the movie. They gesticulate animatedly, show each other things in their phones, and basically completely ignore the actual film.

Which would be fine if they were the only ones there, but there's another boy a couple of rows behind them. He's difficult to make out, especially with how little he moves, almost shrunk into himself. At various times he looks like he's about to get up and say something, but eventually he settles back down, probably thinking better of it.

And then the other three boys' heads explode.

They don't really explode, but they do expand in a way that would be comical if it were less gruesome. It takes a few seconds, and they start expanding one after another, but by the time they notice it their airways are too blocked for them to make any further sounds. They thrash about for a few more seconds before they finally succumb to the changes, and then they are still.

The other boy seemed frozen while that was happening, and still didn't move for many seconds afterwards, but then he suddenly got up and ran out of the screening room. The security camera in the hallway outside does a substantially better job at capturing the boy's likeness than the other ones', and he looks terrified as he runs away.

"The victims weren't changed concurrently. That implies that if two sorcerers attacked at the same time, only one of them can be affected. Potentially useful, but obviously dangerous to test."

Itadori nods. "Probably best to stay away anyway."

“Yes. But better to know than not. Ijichi, keep us apprised of the police’s investigation into the witness. We’re likely going to want to talk to him as well.”

And then they can go follow that trail that might lead them into a trap. Carefully.

Itadori has kept a coating of cursed energy around his skin throughout this, and he reinforces it as he follows Nanami.

Nanami is probably doing the same, but his shielding feels significantly more subtle to Itadori's senses.

The trail leads out into an alleyway, and then up onto a roof.

It continues to rain, and Itadori feels like this is sufficiently obviously enough a trap there's no point in bringing the umbrellas, but to be fair they might as well just in case.

But they haven't taken three steps past the door out before the first curse shows up. It's somewhat humanoid, kind of, green-skinned and with elongated limbs it uses to quickly crawl down a wall and into an alcove sheltered from the rain. It has a short tail that ends in a tuft of long black hair that matches the hair on its head, and its face is stretched into a snout, two eyes bulging out of their sockets and the lips pulled back with the teeth and gums sticking out of its mouth. It looks over its shoulder, still on all fours, and says, in that typical garbled and warped register curses tend to have, "Lu-lu-lunchbox?"

Itadori spreads his legs a bit for stability but narrows his eyes and looks over his shoulder—there it is, a second curse, also more humanoid than most. Its skin is white and paper and its head is stretched and widened into its torso with no neck to separate them. Its eyes and nostrils are squeezed into points, and its perpetually-parted lips show a mouth that opens horizontally rather than vertically, two rows of large square teeth going up-down rather than right-left. "Good detergent," it screeches.

"You take the one behind us," says Nanami, "and draw it towards where we came from and keep our exit as secure as you can. I'll take this one and see if I draw out any more."

"Yes, Nanami-san."

He tosses his umbrella aside and flexes his fingers as he turns around to fully face the white-skinned curse then waits for it to make the first move.

It does, of course. It has… some skill, some level of thought behind its actions besides mindless murder instincts, but it doesn’t feel particularly well trained. Or well formed, for that matter.

Nanami steps forward towards its companion… and begins to monologue?

“My cursed technique is precisely based around proportions, and mathematical. Imagine dividing something by ten. If I strike at exactly the ratio of seven parts to three, my cursed energy creates and then exploits a weakness.”

Is Nanami talking to him?

Tōkan dodges a swipe and offers one of his own but calls, "Were... you talking to me, Nanami-san?"

“Not in particular, though you’re free to listen.”

"...can they understand human speech?" he guesses next.

"Perhaps. I have yet to determine for sure or not."

"Okay, I give up. Why are you explaining your cursed technique, then?"

"Really?" wonders Nanami, sounding a little surprised. He is trading swipes with his own creature, but seems to be seeing what it's doing more than actually trying to kill it. It's not accurate to say he's toying with it, but he's definitely giving it space to observe it. "I thought you would be familiar with pacts already. I'd been told you had one already, with Sukuna."

"I... probably made one that included having my memory of it erased," he says, dodge dodge punch. "If Sukuna explained pacts in detail to me he made sure I would forget about that, too."

"I see. Then Gojo-san was very lax to not explain them to you once that was clear." Swipe, dodge, sidestep. "A pact, or shibari, is in short an agreement to bind or restrict oneself. It can be between two people, like your forgotten one with Sukuna, or," sidestep, "it can be with oneself. It is inherent to human psychology that if you give up ground or make a concession, you can gain something elsewhere. Illogical and incorrect in the reality of cold physics, but the world of jujutsu sorcery is not. It is illogical, it is spiritual, it is emotional. And humans, silly creatures that we are, think it should be fair."

He opens his mouth to say something but immediately closes it and braces himself, both arms in an X in front of him to tank a punch.

Which gives him time to think before asking, and so instead he says, "Your restriction is informing... your opponent, such as they are, about how your skills work. Giving up the element of surprise. And the upside...?"

Nanami seems to have gained all he wanted from watching his opponent. He steps forward, and slashes with terrifying precision and speed. In one arcing slash, he removes three limbs.

"Simply put? Power."

Then he tilts his head and eyes his (wrapped) shortsword. It... is covered in blood.

"...Ah," he says softly. "I see."

Curses don't bleed.

Tōkan was talking but not watching, so he did not see the blood.

Instead he thinks. He doesn't have a cursed technique, but...

"Gojō-sensei said that because of learning to manipulate cursed energy so late there's a delay between when I want to use it and when I actually use it." He takes a leap backwards off his foe, kicking its chest. "So my hits are twofold: the initial hit with raw strength, and then a fraction of a second later the cursed energy for a second hit." Will that work as a pact? Time to find out. He leaps forward again, balls a hand into a fist, and punches: "Divergent Fist."

The first hit dents the creature's chest; the second pierces a hole straight through.

Nanami winces. "Well executed, Itadori-kun, but." He removes his phone from his pocket and takes a picture of one of the severed limbs of his own creature. Because it's not a curse, it shows up just fine. "... I would rather have spared you."

"S...pared me?" he asks, blinking. He walks over to Nanami when he notices the offered phone. "A picture. A curse showing up in a picture? ...not a curse." He remembers the deformed state of the three kids who died in the theater and gets a sick, twisted feeling in the mouth of his stomach.