J-8 is a logical, calculated computer prodigy who spends about 95% of his waking time on a screen. His visor is not actually part of his Quirk, as most people think: it is a device he built himself so he never has to interact with people that he doesn't want to. It has a built-in screen that can be turned into a one-way window, so it's impossible to tell when he's actually looking at someone. He almost never takes it off, and when he does it's only for a short time around his close friends and family. His Quirk gives him the ability to boost his intelligence to genius levels (and come up with solutions to problems at hand), but he has to keep his tail plugged in when resting to supply enough electricity to support his brainwaves. He is not a hero-in-training, but rather, a star student of the support class.

He is also Empath's best friend. J-8 enjoys rambling to an audience who will actually listen, while Empath likes being around him because his calm demeanor stabilizes her emotions. J-8 also shows his humorous side around her, something most students in the support class aren't even aware he has.