The first time Kento saw a cursed spirit he was six.
He was at his cello instructor's house, practicing his posture. The instructor got a call and left the room to answer. Kento noticed a purple, slithering mass shortly after, crawling into the room right in front of his instructor.
Scared, he asked what the thing was, but the instructor said there was nothing, it was just the 2 of them. Not wanting to make a scene & risk losing his cello privileges (his parents weren't keen on him taking up the instrument but his Danish grandpa insisted & paid for it), Kento did his best to ignore the thing. But it was there every day now, growing bigger, uglier, noisier.
He eventually stopped taking lessons not because he said anything but because the instructor was found dead.
Kento was convinced that the thing he saw was responsible but didn't say anything bc no one would believe him.
His grandpa tried to find him another instructor but Kento had associated the curse with the cello and politely declined.
It wasn't until a few months later that he saw another course and understood that they weren't tied to objects but to people. He became withdrawn bc of it, turning to activities that allowed him to be by himself more often. But curses were everywhere, and he wouldn't understand why until much later, when he was scouted to the Tech in middle school.
Furthermore, it would be a few more years after that he would find out that his grandfather could see curses, too.
It hits him hard when he finds out. At this point he's with Satoru, who notices right away that something's wrong. It's like pulling teeth, getting Kento to open up, but he eventually does.
He's angry but doesn't want to be - he understands, logically, why his grandpa never said anything.
He's less confused about where his CE/CT originated but still has many questions that can't be answered bc his grandpa is in no shape to recall and recount.
He's sad that he dropped cello bc of this.
He's glad, though, that he eventually was scouted and met Satoru, Yu, and the rest.
Satoru does his best to put things in perspective, not bc he thinks Kento is lacking in it, but bc he knows certain things are easier to process when you hear them from someone else.
Sure, Satoru's experience was vastly different from Kento's but he's seen it enough times w/his students to be able to provide reassurance.
Kento's grandpa wasn't malicious, he was just trying to protect him. He knows a bit abt the complicated family dynamic Kento grew up in so it's easy to see that his grandpa's approach was likely the best.
Satoru talks him into taking up cello again. He also offers to visit Kento's grandpa a bit more often, not to get more answers abt his family's past but to spend quality time with him & make up for lost time.