Edinburgh lose their captain to Exiles
Coman will move to join the London Irish club at the end of this season.
"It was a really tough decision to move on," Coman said.
"Edinburgh feels like home now and I've had a great two and a half years here, but moving on to a new challenge feels like the right decision at this time."
Coman joined the capital outfit during season 2013/14, from Hawke's Bay Magpies', and was named club captain at the start of season 2014/15.
He continued in the role into this season, leading the team to a European Challenge Cup final and back-to-back 1872 Scottish Cup wins.
He said: "The club has changed a lot since I joined, Solly [Alan Solomons] and the other coaches have done a great job.
"When I first arrived there were a lot of changes going on. When look around now, I see a club becoming sustainable with a lot of young guys who are shaping up to be great for Edinburgh."
Coman, who currently has 48 caps for the club, rates those 1872 Scottish Cup wins and last season's European run as highlights of his time with Edinburgh, topped by his name appearing twice on the captain's board at the club.
He said: "It's been a real honour to be captain of Edinburgh and see my name on that board. There are a number of great candidates to take on the role now, a lot of guys willing to do the job and do it well.
"The biggest thing I'll take away, however, is the camaraderie. I've made friends for life at Edinburgh so it will be really tough to say goodbye."
Head coach Alan Solomons said: "Mike will be sorely missed by all at Edinburgh.
"His contribution both on and off the field has been immense. He is an outstanding leader, a terrific bloke and a really good rugby player.
"Mike is one of the finest men I have met and it has been a pleasure and a privilege to coach and work with him. On behalf of all at Edinburgh rugby we wish him well in his new venture."
