In Lost Dimension, each character has two case files containing the experiments that were placed on them. Every character has two, but one. Agito Yuuki is very close to everyone he meets, even if it was just a small hello, he will become close to them. But, Sho does question why he's so clingy. But I don't think we ever get an answer... With this information, I've come to this theory: Since Agito had only one case file, I think the scientists only spoke and experimented on him once. I think they were so terrified of him they decided to put him in solitary confinement. "Everyone was panicking..." I think everyone was just scared of Agito at first glance. Even the scientist who was working with Zenji thought he was just an innocent kid, but as soon as Agito used his Gift, they were all terrified. So I think that's why he's so close to everyone he meets. It's prolly not a solid theory, but it's just something to think about.