The Japanese utility man, who joined the Hoops at the start of this month alongside compatriots Daizen Maeda and Yosuke Ideguchi, has signed a four-and-a-half-year deal after departing Kawasaki Frontale.
Hatate often competed against Postecoglou’s Yokohama F. Marinos side on several occasions and the 24-year-old claims he has always admired the Australian’s style of play from afar.
Speaking to Celtic TV, Hatate said: “I feel extremely honoured to finally be able to wear this historical uniform, so I’m very happy.
“I’ve only been able to see (the atmosphere at Celtic Park) in videos and pictures so I’m really excited to finally be able to experience a great stadium.
“I’m looking forward to meeting the fans and playing in front of them.
“As a Japanese player, it’s really exciting to see a manager who has experience in Japan and international (football), so I’m just really amazed by the whole thing and excited to join this great team.
“In Japan, I have always been against his team but I have always observed and thought his way of play is very strategic and attacking-led.
“It’s extremely fun for the crowd to watch and I hope to contribute as much as possible.
Hatate becomes the fourth Japanese player to join Celtic this season and he outlined his intention to contribute as much as possible in attack.
He added: “Being able to play in different positions has given me confidence as a footballer and with this team I want to be able to bring out the best in my style of play and contribute to the attacking side of the game a bit more.
“I hope to focus on being the best version of myself so that I can contribute towards Celtic. I want the fans to see how I play as soon as possible. I will do my best in training- as much as in the game as well.”