Joe Hart says he treats Kyogo like he's one of his own kids as he just wants to "protect" the shy Japanese star.
Meanwhile the keeper named Jota as his coolest teammate - as he's taken the George Michael comparisons in his stride.
Former England keeper Hart has been one of Ange Postecoglou's most effective signings this season and has marshalled Celtic to the top of the Premiership.
He's already a fan favourite after his move from Spurs and he spoke to Celtic TV for a Valentine's Day special.
In a segment titled "Love Harts", the stopper was asked to go through a packet of the famous sweets and attribute the messages on them to his teammates.
And there was no hesitation when it came to "shy."
Hart said: "Shy...that's Kyogo.
"English obviously isn't his first language. He's very humble.
"He's an awesome player and one we've come to really appreciate and look to.
"He's not the kind of guy that loves attention but he's a really nice, humble, shy guy.
"As an older person and as a parent I actually want to protect him."
It was an equally swift answer for "cool" as Hart referenced Jota's good looks that have earned him comparisons to rock star George Michael - and he even dressed up as him for the club's Christmas video.
"Jota's pretty cool isn't he?" he said.
"He's got his own little thing going on. He's not being deterred by the fact he's being likened to old school George Michael.
"He's stuck with it and I think we appreciate that."
And Jota's name also came up when "glam" rolled around.
"We're not overly glam as a squad, but that's probably Jota again.
"His barnet takes some maintaining. It's different but he pulls it off."
