WARNING: The following contains spoilers for Boruto: Naruto Next Generations Episode 188, "Awakening," now streaming on Crunchyroll.
The Boruto anime has finally revealed Kawaki to the Konoha ninja squad, and Team 7's absolutely floored to see the Vessel is a mere youngster, similar to Boruto, and not some kind of robot or scientific tool as they expected. In Episode 188, Konohamaru advises them to keep their distance until he can surmise what the kid is, but the ever-trusting Boruto runs over to help anyway. This ill-advised, rash rush of blood to the head inevitably leads to a brawl but, in the process, it also reveals something else that's significant: a dark connection between Boruto and Kawaki's Karma marks.
When Koji Kashin saw Boruto had a Karma mark in their fight he left immediately, wanting to spy on the teen more to see how his powers would evolve. He realized that while Boruto sucked in chakra when his hand activated, he still doesn't know how to master it, and Koji is all about research. This is why Konohamaru is petrified in the latest episode when he spots the same diamond-shaped mark on Kawaki's hand when he's passed out.
Boruto's even more inquisitive, suspecting that when Kawaki comes to, he'll have answers for him on the Karma. Instead, Boruto's suddenly overcome by pain, and we see the mark activating on Kawaki. Enormous amounts of chakra start flowing through and around Kawaki, creating a purple protective barrier, leaving everyone scared of what's about to happen. And they're right to be. In the blink of an eye, it blows them away, leaving Kawaki levitating like a god but as he lands and his rage subsides, so too does Boruto's pain.
Just as their marks switched on at the same time, they're both off again, leaving Team 7 curious about their obvious synchronicity. They're acting as sensory beacons, too, evidenced by Boruto and Kawaki feeling each other's emotions, awakening the 'Hulks' within. The marks also make the pair come off like brothers, akin to when Sasuke and Naruto got in-sync with each other as descendants of Indra and Ashura, respectively. From this brief amount of data, Konohamaru can tell there's resonance in the marks, and that both the boys are inherently connected.
But he's even more worried by the fact that Boruto got his mark after killing Momoshiki, and, as the sinister Garo reveals when he comes to retrieve Kawaki, the other boy got his in a lab under the watch of Kara. This leaves Konohamaru to wonder if the marks are man-made, engineered from the alien invasions by the Ōtsutsuki, or something new that not even Katasuke could dream of. Either way, as Kawaki powers up again and goes after Garo in Episode 188, Konohamaru has to keep an eye on Boruto more closely as he can tell if one goes overboard, expending their powers with the mark, the other might die.