Kyogo Furuhashi revealed former Celtic teammate and Japanese countryman Tomoki Iwata talked him into signing for Birmingham City.
And he turned down offers to move elsewhere to go to the English Championship.
The ex-Hoops hero cut short his disastrous six-month spell in France with Rennes to seal a £10 million move to St Andrews.
And, in an interview on Japanese television, he admitted he listened to former Parkhead colleague Iwata, who joined Birmingham from Celtic a year ago.
Kyogo said: "I was happy because I received many good offers, but I decided Birmingham City's was the best for me.
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"Tomoki Iwata contacted me and told me he'd be really happy if I joined him at Birmingham. I listened to what he had to say about the club and I got really excited about hearing about their ambitions.
"I'm looking forward to working with Iwata again and I hope I can help the team achieve their goals this season.
"It's true that I had a difficult period at Rennes, but I don't regret going there and I think I grew in some ways, so I believe I can make use of that experience in Birmingham and I hope to make the most of it.
"My aim is to get back playing regularly - that's my biggest hope.
"I also want to enjoy football again, score as many goals as possible and become a player who can impress many people and bring smiles to their faces.
"I want to be a leader on the playing side as well."
