Matt plays in the fly-half (and occasionally inside centre) position for The Ricoh Black Rams.
McGahan is eligible to represents Japan at international level after qualifying on residency grounds.
McGahan came to the attention of national selectors at the age of 17, after he was selected in the New Zealand secondary schools team against Australia in 2010.
After three seasons with the Storm, McGahan had made 54 appearances in the NRL Under-20s competition scoring 421 points.
He left Melbourne following the 2013 season, returning to New Zealand and the sport of rugby union.