|“||I want to find methods that work for everyone and then mass-produce Perfect All-Rounders. My long-term goals are different from Kō's.||”|
Arafune is a light-skinned, lean young adult with messy, medium-length brown hair. He is often seen wearing buttoned shirts and leaving the top buttons undone and a black cap with a turquoise visor. At Border's HQ he wears casual clothes, such as a skin-tight black shirt and a light-colored sweater he keeps tied around his waist. His unit's uniform consists of a jet black jacket with turquoise stripes around the raised collar, along the zipper, around the hem and the wrists, and white ones around and inside the raised collar and on the outer side of the sleeves. There are also four white lines, arranged in two columns of two, to each side of the zipper. Above the topmost left white line is the B-rank logo with the unit's position emblazoned on it. The attire is completed by jet black pants, boots, and the same cap he wears in his casual clothes to keep the sun out of his eyes.
Arafune may come initially across as rude due to his habit of not mincing words and his manner of speaking occasionally being coarse, but he is considered a nice guy by other Border agents, and he was seen speaking harshly only to or about his friends and people who would not get upset. Although he enjoys competition and combat and can be observed smiling before and during rank battles he does not resent agents who best him. When the stakes are real, such as during Neighbor attacks, he is serious, focused and keeps his speech neutral and to the point. He is very self-confident and ambitious, his aspiration being not only to become the first Perfect All-Rounder since Reiji Kizaki, but also to develop theories based on his experiences to mass-produce Perfect All-Rounders.
Arafune and Murakami were originally a mentor and disciple, but when Arafune reached Master Class he switched to Sniper. Like many others, however, Murakami assumed that Arafune quit because he resented him for surpassing him in only six months. When he found out about Murakami's state of mind, Arafune sent him a video whose aim, despite the Sniper sounding as though he was rebuking Murakami for getting cocky, was to reassure him that he did not hold a grudge against him. The two are currently friends. Arafune calls Murakami by his first name without honorifics, while the no. 4 Attacker uses Arafune's surname, he too without honorifics, the reason being that he thinks it sounds cool (implying that it is not because they are not close enough for him to do so).
Arafune appears to respect Kizaki, probably not in small part due to his goal of becoming the second Perfect All-Rounder, Kizaki being the first. Though Arafune originally referred to Kizaki by his surname followed by the honorific -san, but he switched to calling him by his first name after seeking his guidance on how to achieve his goal. The two might have also become closer due to Arafune becoming interested in weight muscle training.
Arafune and Kageura appear to be on good terms, with Arafune referring to the latter by his first name without an honorific and recognizing his superior skill as an Attacker. Kageura refers to him by his surname, without honorifics. Arafune is a regular customer of Kageura's family okonomiyaki restaurant, although he does not seem to be part of Kageura's closest circle of friends.
Arafune enjoys a friendly rivalry with Yūma, and the two have sparred in solo matches on at least one occasion. Despite claiming to want to teach him humility, Arafune is impressed with the wealth of Yūma's fighting experience.
Arafune's relationship with Midorikawa is similar to the one he has with Yūma, feigning outrage at his junior getting cocky and challenging him to teach him a lesson. He seems to be closer to Midorikawa, wrestling with him after hearing that he had predicted his defeat at Yūma's hands. For his part, Midorikawa does not shy away from teasing Arafune.
When Arafune quit being an Attacker Kuruma seemed to disbelieve that it was because of Murakami, which, together with their organizing a get-together, suggests that he already knew him in some capacity. However, Kuruma was unaware of the former Attacker's ambition to develop a master theory to mass-produce Perfect All-Rounders, which greatly impressed him. Kuruma refers to Arafune by his surname followed by the honorific -kun.
Arafune gave Ema advice on the matter of the away expedition, possibly suggesting that the two are close enough for Ema to be willing to share his dilemma and his crush with Arafune. Arafune addresses Ema by his surname without appending an honorific.
Arafune and Nire appear to be on good terms, with her greeting him enthusiastically when they met at Kageura's restaurant and he smiling back at her. She calls him by his surname, without honorifics.
Betsuyaku originally assumed that Arafune had quit being an Attacker due to being dwarfed by Murakami's talent, but after listening to his recorded message, he learned the truth and concluded that Arafune was in reality a very kind person. Betsuyaku refers to him by his surname with the honorific -san.
- (To Tamakoma Second) "Amateurs! You gave yourselves away!"
- (To various people) "I'll cut you down to size."
- (To Kuruma) "I want to find methods that work for everyone and then mass-produce Perfect All-Rounders. My long-term goals are different from Kō's."
- (To Murakami) "Hey Kō, sounds to me like you're drunk on your own power. You think just because you beat me, now you're king of the world? You're 'stealing everyone's hard work'? My teaching skills are just that good! Don't be so full of yourself! That crap should be saved until after you beat Tachikawa, Kazama and Kage! All right?"
- "They don't bite, do they? I don't like dogs..."
- (To Ema) "If you're so worried about her then go protect her yourself!"
- Arafune likes okonomiyaki (a type of Japanese pancake), chilled tofu salad, action movies, and tea and dislikes dogs.
- The reason behind his fear of dogs is that he was bitten by a small dog on his right butt cheek for no reason when he was young, leaving a scar that still remains even now.
- He is unable to swim, to the point that he is reluctant to submerge his face.
- He goes to a prep school and is one of the few B-rank agents with good grades.
- Arafune is considering getting a motorbike license.
- He erroneously assumed that Yūma had been taught by Kizaki and Yūichi Jin, when in fact his only mentor in Border was Kirie Konami.
- In the magazine release of Chapter 87, Arafune's uniform is erroneously drawn with the white stripes colored in. This was later fixed in the volume release.
- The author joked that since he often draws Arafune jumping off buildings, the Sniper chooses them precisely so that he can leap off later.
- His voice actor, Eiji Takemoto, also voices Katsumi Karasawa.