His given name, Yoichi (世よ一いち, Yoichi?), means "world's best."
Yo (世よ, Yo?) means "generation, world, society."
Ichi (一いち, Ichi?) means "one, first, best." Phonetically, it can refer to Yo (四よ, Yo?) and Ichi (一いち, Ichi?) meaning "four" and "one" respectively, referring to his birthday, April 1st. His surname, Isagi (潔いさぎ, Isagi?), means "undefiled, pure, clean."
Phonetically, it can also refer to the kanji's adjective form, Isagiyoi (潔いさぎよい, Isagiyoi?), meaning "sportsmanlike, manly, brave."

Soccer player

She is unnamed yet but she would prefer to be called Hyoma's sister or older sister

Cheerful, sweet, Chigiri sister

focused, disciplined, organized, confident, and ambitious. Kafka can do this by setting clear and attainable goals for herself and then taking steps toward achieving those goals. This can include staying focused on her objectives, setting a schedule to help her stay organized and on track, and believing in her abilities and potential. Adopting these qualities, she professional with violin.

"You won't remember a thing except me"

His given name, Hyoma (豹ひょう馬ま, Hyoma?), means "leopard horse," referring to his great speed.[19]
His surname, Chigiri (千ち切ぎり, Chigiri?), means "julienning" or, literally, "a thousand cuts."[20]
His name can thus be interpreted as "leopard horse with a thousand cuts."

Blue lock-speed prodigy, red Panther, manshine cit

His given name, Reo (玲れ王お, Reo?), means "king of jewels."
Re (玲れ, Re?) means "sound of jewels," referring to his rich background.
O (王お, O?) means "king, ruler, magnate."
His surname, Mikage (御み影かげ, Mikage?), means "divine spirit, spirit of the dead."
Mi (御み, Mi?) is an archaic honorific suffix added to refer to things of divine importance or to indicate godlike respect.
Kage (影かげ, Kage?) means "shadow, silhouette, phantom," referring to him being often considered Nagi's shadow.

Husband Au, Chameleon, midfielder

His given name, Reo (玲れ王お, Reo?), means "king of jewels."
Re (玲れ, Re?) means "sound of jewels," referring to his rich background.
O (王お, O?) means "king, ruler, magnate."
His surname, Mikage (御み影かげ, Mikage?), means "divine spirit, the spirit of the dead."
Mi (御み, Mi?) is an archaic honorific suffix added to refer to things of divine importance or to indicate godlike respect.
Kage (影かげ, Kage?) means "shadow, silhouette, phantom," referring to him being often considered Nagi's shadow.

Manshine City, Chameleon

His given name, Hyoma (豹ひょう馬ま, Hyoma?), means "leopard horse," referring to his great speed.
His surname, Chigiri (千ち切ぎり, Chigiri?), means "julienning" or, literally, "a thousand cuts."
His name can thus be interpreted as "leopard horse with a thousand cuts."

Husband Au, blue lock speed prodigy

His given name, Seishiro (誠せい士し郎ろう, Seishiro?), means "sincere son of the samurai."
Sei (誠せい, Sei?) means "sincerity".
Shi (士し, Shi?) means "samurai, warrior."
Ro (郎ろう, Ro?) means "son."
His surname, Nagi (凪なぎ, Nagi?), means "calm, lull."
His name can thus be interpreted as "calm and sincere son of the samurai."