. Ayano, when she was a mind controlled drone, was often ordered to teach Hikaru a lesson whenever he did something the higher ups disliked.

. Hikaru has many unpleasant memories associated with Ayano, as she's the reason that he has the scars on his back.

. Hikaru has extreme trouble sitting around and doing nothing. But other times it's all he wants to do.

. Hikaru hates rock, metal, and classical music. The reason for this is rock and metal is loud and harsh and makes him feel very anxious, especially because of his upbringing. Classical music brings about PTSD because it was played in the background whenever he was punished, or he'd be placed into a dark room where he couldn't feel any walls and would be played so loudly it was the only thing he could hear.

. Hikaru hates violins because the loudest note is sharp so hurts his ears very badly. His ears work better than most others' since he's blind.

. Hikaru didn't know of other styles of music (besides rock, metal, and classical) until he was 13, when he was found by Mirio and Mai and taken to the hospital. (Mai belongs to SpamChan.)

. ESTPs truly hate being bored, and will often try to find a way to escape their boredom. They will seek out friends to go on adventures with, and might even take a long road trip. ESTPs will do whatever it takes to escape their boredom, and are often great at finding new ways to entertain themselves.

. Much like the ISTP, ESTPs become intensely bored if they are forced to stay stagnant for too long. They enjoy exciting activities that keep their minds busy and distracted. They enjoy learning, but above all else they enjoy seeking out new thrills and adventures. ESTPs want to be able to feel excitement in their lives, living very much in the present moment. If the ESTP is forced to stay still for too long without something to keep them busy they will become quickly bored. ESTPs enjoy realistic ideas and information that they can absorb and understand. When the ESTP isn't capable of keeping busy they will become annoyed and bored.

. Hikaru's turtle shaped scar on his calf has come to mean more to him than being slow and weak. Someone helped him realize that slow and steady wins the race, and that turtles truly are strong.

. He's once been said to be like a turtle for the fact he has a shell around his heart to protect himself. Same goes for his emotions— which are already included when one says heart.