Denki is a friendly, social, and energetic boy who enjoys hanging out with others. He is rather casual when interacting with other people, including the generally unfriendly people. He may come off as blunt and reckless at times but is always well-meaning. He encourages others to be themselves and become more comfortable doing what they like. He is somewhat flirtatious towards the girls in and out of his class, sometimes accompanying Minoru Mineta on his schemes and trying to pass himself off as a smooth talker. He is not very lucky with his approaches, though, frequently having his advances ignored or outright rejected by those he asks out. He is also a bit of a jokester and sometimes teases others with playful comments. Overall, he is interested in appearing cool and trendy to impress people but has a shallow understanding of how to do so correctly. Because of that, he is easily influenced by what's popular or stylish at the moment.

Denki could be more academically bright, requiring massive help with studying due to his general disinterest and neglect of school duties. He does not appear to pay much attention in classes, gets quickly bored from lectures, and suffers anxiety attacks when dealing with tests, at which point he becomes increasingly agitated and aggressive. Frequently showing a lack of tact and smarts in and outside of school, he may give off the impression of being stupid or foolish, leading others to throw snide remarks at him. Despite this, he can show surprising knowledge about specific areas such as literature, art, and music, possessing an extensive vocabulary that shows up now and then. He becomes distraught when put into stressful situations, appearing spineless and incompetent to foes and allies alike. 

During combat, he is swift to panic and may accidentally activate his Quirk in the face of imminent danger, leaving himself vulnerable. He becomes more reluctant to use his full power when there are allies close to him, being afraid of hurting them through collateral damage from his explosive bolts. He becomes more confident in his fighting abilities when he is assured that all his allies will be safe from his powers. He does not tolerate others looking down on him, and his classmates and will defend them if necessary. Whenever Denki exceeds his wattage limit, he loses his ability to discharge energy, with his entire personality changing into that of a giggling idiot for a certain period until he reverts to normal. In this state, he is always giving thumbs-ups as a way to let others know that he is okay.

If you could sound similar to his English VA, Kyle Phillips, that would be great, but it is not required! English VA Example: From 0:09 to 5:06 of https://youtu.be/0gytTAmdpNQ