Akaashi has messy black hair and gunmetal blue eyes with thin pupils and slightly thick eyebrows; in some official art, his eyes appear to be green, but in others, they are more blue-colored. He tends to wear an emotionless or slightly exasperated expression a great majority of the time but is shown to smile occasionally given the circumstance.
He makes his debut at the beginning of the Tokyo summer training camp wearing a navy T-shirt with a light aqua sports bib on top, the number 5 printed in black, altogether with a pair of white shorts. His shoes are white with yellow details, and he doesn't appear to be wearing kneepads during practice.
When dressed in his school uniform, he wears a light grey blazer and black trousers, held up by a black belt. His shirt is neatly tucked into the waistband, and his blue tie is knotted neatly.
Akaashi can be seen as calm and composed most of the time, usually choosing not to show a wide range of emotions. He has a habit of calling people out on the foolish things they do. Especially Bokuto, who he seems to be relatively close with despite their opposing personalities.
As opposed to being shy, Akaashi is somehow blunt with the things he says and often invites himself into the conversation when necessary, throwing in witty comments or responses. Although he is polite to a certain degree, this could be due to the fact that he is younger than most of his teammates.
Akaashi also has a strong analytical side which can be seen whenever he makes split-second decisions on how to save the game from Bokuto's mood swings. It took him .5 seconds to decide whether or not setting the ball to Bokuto while he was upset would be worth it or not.
In addition, he is also humble, knowing his own limits in his skills and never overstepping his boundaries.Then again, he also holds a cheeky trait, as he had dubbed Kuroo during one match; 'The pain-in-the-ass-Kuroo-san'.
Akaashi is overall a very balanced player and a good setter who can accurately set the toss for a wide range of attacks. He has been noted for his strategic skills as well, and his ability to perform a quick-set even when the receive is a bit sloppy.
He is also really analytical. During the Nekoma-Fukurōdani match, when Bokuto forgot how to do cross spikes, Akaashi was able to successfully revive Bokuto. He was also complimented on this by Nekoma's coach after the match.
Jumping Reach: 327 cm
- One Person Time Difference Attack: Although Akaashi hasn't done this attack on screen yet. It is known that Akaashi has been practicing this skill with Tsukishima during the Summer Training Camp, which enables Tsukishima to use this technique against Shiratorizawa with Kageyama setting.
- Toss Rebound: During the match against Mujinazaka High, a receive by Konoha was made too long. Unlike other talented setters such as Kageyama who would normally toss it perfectly despite the off receive, Akaashi rebound the ball against the blockers by tossing it, giving his team another chance to attack.
- His favorite food is boiled rapeseed plants with karashi mustard dressing. (Nanohana no Karashiae)
- His current concern: I want my physical power level a bit higher.
- His star sign is Sagittarius.
- He has a habit of fiddling with his fingers, much like Tsukishima; this can be seen in the manga in several panels and official arts as well.
- Akaashi is known to have larger hands than Bokuto (according to the Haikyuu store)
- He has been observed to enjoy onigiri, also known as Japanese rice balls.
- He doesn't wear the t-shirts Bokuto recommended even though he himself has worn some weird t-shirts as stated by the wing spiker.
- Keiji (京治) - Keiji is a popular boys' name in Japan, out of which 京治 is a rare writing of the name in kanji - more common versions include 慶次, 啓治, etc. 京 means "city", while "治" means "to govern/to cure". It is likely that this is simply an attempt by the author to transcribe the sound "keiji" to kanji, and is unlikely that the literal meaning of the kanji carries any significance or meaning.
- Akaashi (赤葦) - This is probably a reference to the アカアシモリフクロウ (akaashi-mori-fukurou), known as the rufous-legged owl in English. Note: the species of owl is not written as "赤葦" ("赤" meaning red, and "葦" meaning reed) - again, this is likely to be a transcription of the katakana into kanji, and the literal meaning of the kanji is likely to be insignificant.