13 is often seen wearing a hat with a stripe down the top, a worn jacket with spikes on the shoulders, a plain, grungy t-shirt with the number "13" on the front, tight pants, and some sort of skirt like apparel that appears to be plaid.
He has two red stripes on each of his cheek, sunken eyes with small pupils and large bags underneath and pointed teeth. 13 has dirty blonde hair that is fairly short unkempt hair and reaches the back of his neck.
13 is very laid back, but seems to be very emotional if his reactions are anything to gauge by. He is quite to react with extreme emotion such as irritation, fear, anger, and occasionally more joyous feelings. 13 is somewhat of a coward and often shies away from danger. He shows romantic interest in Nikaido early on, though not as serious as Kaiman's clear attachment, but later in the series it seems to simmer into more of a loyalty of friendship.
Presented as a customer in Nikaido's restaurant, coming to eat some gyozas (Kaiman is automatically pissed about this believing he want to eats his precious gyozas), Vaux also appears sulking about how they will unable to play againts the Sharks unless they find another player, 13 enrolls in the team.In the mach against the Heiwa Clinic Sharks, 13 ask Kaiman what kind of relationship he has with Nikaido, the lizard head simply replies that they are friend, 13 mentions if he don't mind if he tries to go with her, Kaiman tells that he can always try. Nikaido is at the bat and Fujita (the other team pitcher at the time) is so pissed of about her that aims directly to her head, 13 is concern about how little Kaiman seems to care about it, the lizard head tells him that he should know Nikaido better.13 appears once again after Kaiman left Hole to go to the sorcerers realm, looking how crowd the Hungry Bug is, he congratulates Nikaido for the business success, she replies that all is because Kaiman is not there to scare the customers.
During Dr. Vaux Birthday, Nikaido, the doctor, Kasukabe, Jonson and him were celebrating when the professor finally reveals that Nikaido is in fact a Magic User, 13 is the only one confused, concerned and scared of the notice but in the end he get used to it.
In that moment they are attacked by a mushroom monster that grown from Nikaido's back, after she was able to destroy it, everyone including him where teleported to En's mansion in the magic user world, before he could do anything, his head was transformed by the sorcerer into a big mushroom and everyone was imprisoned in cells inside the mansion.
13 spent days sulking in a cell along with Kasukabe and Jonson, not knowing what was going on for not having eyes. In the end thanks to Jonson's ability to talk with other cockroach he was free along the rest and ultimately ended healed by Noi once Kasukabe and Shin met once again.
After a party celebrating the reunion between the doctors and Shin, 13 and the rest disguised as Goons and stole a minivan to go and find Kasukabe's Wife in the Hydra Forest, believing she could help to deliver a message to Kaiman in order to let him save Nikaido from En.
When they arrived to the cabin, they where welcomed by a gruesomely Frankenstein-like magic users with Crosses in their eyes. One of them injured 13 and Kasukabe quickly told Vaux to grab the wounded young man and hide anywhere in the cabin while he and Jonson dealt with the sorcerers. Without hesitation the doctor and 13 hid for god knows how long and even started to wonder if everyone forgot about them.
Once the cabin was destroyed and all of them where saved by Shin (angry at them for go without explain anything), Vaux asked the professor if he felt bad for not be able to find his wife, to his surprise, Kasukabe told that he indeed met her.
The group went back to the mansion and stayed until Kasukabe told the cleaners about that he saw in the cabin, and eager to find clues about "The Cross-Eyes Boss" 13, along the rest, finally went back to Hole, happy to see his world again, and kinda grossed about the remains of Vaux's birthday party, days after they left, the Hungry Bug was wrecked and the food was totally spoiled.