But a life… You can’t get that back.❞
In colored manga illustrations, Shinkai is drawn with blue streaks in his reddish brown hair. In the anime, his hair is a solid reddish color, which grew longer from his second year, and he did have a side-part hairstyle, whereas now he has bangs. His heavily-lidded eyes give him a generally relaxed look. His eyes along with his thick lips are his defining facial features. He is often depicted with a power bar in his mouth or striking his signature "Bang!" ("bakyun") pose, which is making a shooting motion with his hand. His casual wear is usually a yellow 'Lip Street' shirt with big lips like the Rolling Stones logo, with sleeves rolled up.
Shinkai generally has a very laid-back and placid personality. He shown to be very caring; when he ran over a rabbit with his bike, he deeply regretted his actions and decided to raise the rabbit's orphaned kit. This event also traumatized him badly, so he didn't want to participate in races anymore because he felt his obsession with winning was dangerous. According to him, a loser can try again, but a life is something that can never return. Out of guilt, Shinkai rejected the offer to participate in the Inter High as a second year, but participated in his third year because of the support of his teammates. He enjoys food, as seen by the fact that he is often seen eating power bars and is able to eat large amounts of food, such as extremely hot curry.
Shinkai can come across as aloof, perhaps because he doesn't say much, but when he interacts with others he's actually very endearing and affectionate towards his team, teasing them constantly and brimming with confidence. Shinkai reads many mystery novels and will perform his signature "Bang!" pose when he sees something he likes. He almost always refers to those closest to him by their given names, as opposed to their family names, which is a very intimate way of speaking. If they aren't someone he knows well but share the same "status" as him (for example, another third-year student), Shinkai calls them by their given name but attaches the suffix -kun.
When cycling, Shinkai can be very quiet and not stand out much until it's his turn; he doesn't become emotional under pressure. However, when facing off with other cyclists, he becomes a serious force to be reckoned with. In the past, before the accident that scarred him, he was called the "the straight-line demon" when his determination to win became particularly strong. In this state of mind, Shinkai becomes almost manic in his attempt to win, living up to the "demon" part of his nickname. This part of him resurfaces when he's able to overcome his trauma that prevented him from passing on the left side. His actions illustrate his desire to live up to the expectations of the team that cares for and supports him.
Skills and TechniquesAccording to Fukutomi, Shinkai has a high natural ability when it comes to road racing, game sense, athleticism, and explosive power. It's this and his extreme desire to win that makes him the fastest sprinter in the Inter High.
His speed is top-notch and he is considered the fastest sprinter among High school road racing competitors, perhaps even better. He seems to pace himself and not use his full speed unless needed; as shown when Midousuji posed a threat on the 2nd day of the Inter-High.
His full power known as the "Straight Line Demon". This technique has been known to drag his opponents down by any means possible. This name was given to him because his opponents trembled when they looked at his frenzied face, which usually has his tongue hanging out. What's more, this mode makes him demonically faster than he ever was.
He carries multiple power bars with him and snacks on them frequently during races. He even carries them into weird places like in Ofuro or in sauna. He was also seen eating them when he congratulated Izumida's win on the Second stage's Sprinter's Checkpoint in the 42nd Inter High. Later, he invited the reserve riders to meet Fukutomi, who also was wearing the orange Meisou University Tops
- Chocolate and bananas (his PowerBars are also that flavor). For chocolate, he likes dark chocolate
- Kotatsu with satsuma oranges
- The cold time of the year (since he's sensitive to the cold)
- Reading detective novels
- Shinkai's rabbit, Usakichi, is female, and appears light brown in the anime, but has appeared all white in a colored manga illustration. Because the illustration is during winter, Usakichi may be Lepus brachyurus, a Japanese hare. She remains at Hakone after Shinkai graduates.
- Shinkai's signature "bakyun" pose is often romanized as "BQN!"
- He eats as much as Tadokoro. He also likes Japanese snacks and can eat a whole cake by himself.
- He owns a Parrot.
- He has fan club but he doesn't react to much despite their screaming.
- Shinkai's ideal type of girl is someone who is quiet and gentle.
- His hair is naturally colored, but he highlights with blue streaks.
- His hair style doesn't change even after he becomes a university student.
- He went to the same university as Fukutomi, Meisou University (Lit. means Tomorrow Morning University), after graduating and lives in the school dorm.