Rapt has a lizard-like appearance. His head is a long oval shape, his sharp-toothed mouth stretching the whole way across it, and he possesses large, reptilian eyes. His nose appears to just be two small nostrils, and he also has a tail.
He wears a hooded jacket, a waistcoat, and simple shorts.
After taking Trigger, Rapt becomes even more lizard-like and grows wings.
Like Soga, originally he was a bully who enjoyed humiliating others and watching other people being humiliated by his friends. He was also usually the first to laugh at others.
Despite this, he shows concern for his friends and helps them whenever he can. He also has a more humorous personality, liking to make jokes and teasing his friends. He has some sense of responsibility, learning from his mistakes, such as when after being hospitalized because of Trigger, he decides not to use it again despite the good experience he had.
Rapt Tokage meets Koichi Haimawari when he unwittingly bumps into him and his friends and spills Soga's juice. They try to humiliate Koichi, but he runs away. They chase him, but Koichi manages to escape. Later, they encounter Koichi again at the convenience store he works at, and this time they beat him.
Later that night, Koichi and Kazuho Haneyama meet the thugs in an alleyway, and they recognize the latter as the online idol Pop☆Step and pin her to a wall while expressing their intentions to sexually assault her. Koichi tries to stop them but gets beaten again. Suddenly, Knuckleduster appears to help him and defeats Soga, Rapt and Moyuru with ease, but not before asking if they have a black colouration on their tongue.
Wounded and bruised, the three thugs move away. Soga has a desire to take revenge on Koichi and Knuckleduster, although his friends try to convince him otherwise. At that moment, Mario Kugutsu appears, offering them samples of Trigger assuring them that their wounds will be healed.
The next day, while doing their duties as Vigilantes, Koichi, Kazuho and Knuckleduster approach Mario, who Knuckleduster suspects of being a Trigger dealer and tries to arrest him by force. Koichi and Kazuho think he is rushing into his accusations, but Knuckleduster is about to hit him, being stopped by Eraser Head, starting a fight between the two.
While this happens, Mario escapes, and Kahuzo realizes that there is something fishy about him and chases him along with Koichi. During the persecution, they meet again with Rapt and Moyuru, who were there to take revenge. They take a dose of the drug that Mario gave them, transforming into Instant Villains. While Soga and Moyuru attack Koichi, Rapt goes after Kahuzo, who is still chasing Mario.
In desperation, Mario injects a sample of Trigger, transforming himself into a gigantic four-armed being with a childish personality. He grabs Kahuzo and Rapt and begins to play with them, like they were toys. Rapt ends up being hurt by that, and before his situation gets worse, Shota, who had already arrested Soga and Moyuru with Knuckleduster's help, nullifies Mario's Quirk with his and arrests him.
Rapt ends up in the hospital because of his injuries, being visited by his friends Soga and Moyuru. Although Rapt doesn't deny that he enjoyed the power and abilities that the Trigger produced on him, when Soga asks him if he would consume the drug again he says no, because the drug is the reason why he ended up hospitalized.
After the accident, Rapt begins to undergo a behavior change for the better, and now helps Knuckleduster take care of his hospitalized daughter while he is out, with Soga and Moyuru.
Unnamed Lizard Quirk: Rapt's Quirk appears to be a lizard-based mutant-type Quirk. The extent of his Quirks abilities are unknown.
Under Trigger's effects, he becomes more lizard-like and grows pterodactyl-like wings that give him the ability to fly.
- His name contains the kanji for "ten" (十?), "day" (日?), and "summer" (夏?) and is pronounced like the Japanese for "lizard" (蜥蜴 tokage?).