Kara motive/plans (Manga Spoilers)spoiler. Lately in the anime Sumire seems like she is very eager to participate in the exams. I don’t think she will suddenly have a change of heart and decide to do ninja tech research. I mean she is even planning ahead trying to find how to beat Boruto and Mitsuki. I think Sumire will be an important character in the series for a few reasons. #1 she is interested in Boruto. #2 she was introduced in the Manga. #3 she is the main villain in the first ark.
I think someome is making Sumire not participate in the exams. And that someone is Katasuke. Sumire has no parents so she is an easy target. Maybe that is why Katasuke was placed under a genjutsu from the Kara. And the Kara is interested in Sumire’s hand seal. I mean as of right now it seems weird to me that Kashin Koji would enter the leaf village and place a random scientist under genjutsu for no reason and ultimately fail to accomplish whatever it was he wanted from Katasuke. Kara shouldn’t be interested in Boruto by the time Katasuke is placed under genjutsu seeing that he doesnt have his seal yet in the anime. In this theory, Sumire is the first target from the Kara and Boruto is the second.
Kara is interested in Sumire’s seal because it is an Otsutsuki seal (Sasuke linked it to Kaguya) and Kara is interested in Boruto’s seal because it is Momoshiki’s seal. I find it too coincidental that KATASUKE (who was placed under genjutsu by KARA (and organization interested in seals) has SUMIRE (hand seal) and BORUTO(hand seal) in his grasp. If Katasuke is working for Kara or is still unknowingly being controlled by Kara currently in the manga, he could be trying to study Boruto’s seal secretly. He gave Boruto a chakra blade (which absorbs user chakra) and the hand glove (Absorbs jutsu) these tools could be studying Boruto’s seal without Boruto knowing. Kara probably doesn’t think Boruto is an easy target like Sumire ( his dad Being Naruto fucking Uzumaki)
In chapter 18 Boruto asks Sumire if she didn’t partake in the chunin exams because she desired to be in the scientific research lab and she doesn’t answer, Katasuke answers for her saying she is one of the most loyal subordinates. Later Boruto asks Sumire if she trusts Katasuke (Boruto is suspicious of him) and she obediently says yes. Later Katasuke is in the room when Naruto explains over the phone to Boruto that Konohamaru needs help and Katasuke just tags along for no reason to visit Kashin Koji/ Ao. Maybe in the next chapter Kashin Koji will address Katasuke and expose him as an inside man.