|“||Hey, no way! We gotta keep this pace until Oki takes out Amatori!||”|
Mizukami is a tall, thin, light-skinned young man with a voluminous shock of messy, orange hair and small eyes with light-colored slit irises.
Mizukami's uniform is comprised of a vermillion, white-zipped jacket. A horizontal white line runs across the chest portion roughly at the height of his armpits, whereas on the back it bends into a flat V-shape pointing downwards, with an ornamental button right above the tip. On the right breast, the white line encircles Border's logo, above which is emblazoned the B-rank emblem. Everything above the white line is black in color, including the high collar, which Oki keeps open to reveal a round-collared undershirt; the only exception are the vermillion plain button epaulets. The sleeves are also black until roughly halfway through the humerus, after which they turn vermillion, and disappear into Mizukami's thick gloves about an inch past the elbow. The gloves are black with a gray palm and a thin brown buckle that encircles them near the cuff. The black portion of the sleeves and the collar bear a square motif that suggests padding. The uniform is completed by black pants with front and back pockets, gray-brown boots that reach halfway up Mizukami's calves, and a pair of rectangular goggles with protruding lenses and a vermillion strap which he keeps around his neck, lenses at the front.
Like most of his teammates, Mizukami is laid-back, although he tends to be more aware and mindful of the circumstances of a rank battle. Despite not being the captain, he is the de facto tactician of the unit, monitoring the state of the battle and assigning tasks to his teammates. On these and other occasions he may appear slightly cold, surly or querulous. However, it seems that the only shortcomings to get him even fleetingly upset are his own.
Ikoma and Mizukami appear to be friends. Despite his pragmatism, the Shooter listens to Ikoma's rambling anecdotes attentively, often providing humorous commentary on or a grounded reaction to them and his outlandish behavior. Despite being the captain, Ikoma relies on Mizukami's tactical insight during rank battles, although when multiple paths are open the Shooter lets the Attacker decide which one to pick before focusing on how to achieve it himself. Mizukami addresses Ikoma by his nickname, to which he happens the honorific -san.
Mizukami appears to be attracted to the Operator, blushing as he complimented her together with his teammates. His words being more restrained than theirs could suggest that he is attempting to keep his infatuation a secret. He addresses her by her nickname, without honorifics.
Mizukami is not enthused by Ikoma and Oki's back and forth about the latter's popularity, although he will exploit it to spur Oki into action during rank battles. In fact, during a match Mizukami can often be heard egging the Sniper on. He most commonly addresses him by his surname without appending a honorific.
- (To Maori Hosoi) "You got your cute points, Mario!"
- (To Tatsuhito Ikoma) "You just gotta try again, don'cha?"
- (To Ikoma) "You're imagining things. You totally just missed!"
- (To Kōji Oki) "Don't blow it. Yer gonna lose popularity."
- (To Oki) "Pull yourself together! We're comin' to ya now!"
- (To Ikoma) "You lost the will to fight really fast...!"
- (To Ikoma) "Hey, no way! We gotta keep this pace until Oki takes out Amatori!"
- (To Hyuse) "Took long enough. But you're done."
- (To Oki) "Seriously, Oki? Y'couldn't've use those skills to save our butts instead?"
- "Satoshi" (敏志?) is composed of 敏 ("fast, quick, clever, smart"?) and 志 (purpose, will, determination, aspiration, ambition, annals?). "Mizukami" (水上?) means "on water, aquatic, maritime, overwater, headwaters".
- Coincidentally, his name has the same reading as that of the manga author and illustrator Satoshi Mizukami.
- Like the rest of his teammates (with the exception of Minamisawa), he speaks in Kansai dialect.
- He likes rakugo, shōgi, udon, and spring rolls. The former is also his hobby, and he has memorized between 20 and 30 classics.
- Despite not going to an elite school, Mizukami has excellent grades.
- Ōji's nickname for him is a pun on his surname and the English word "coming", due to the similar pronunciations in Japanese.
- His icon is broccoli due to the shape of his hair resembling this vegetable.
- The author gave Mizukami the moniker of "Lying Broccoli" due to his habit of calling the wrong Trigger on purpose and the shape of his hair, and describes him as a "beta-carotene-rich vegetable."