The 22-year-old signs from National League South side Eastbourne Borough where he was a regular in the team throughout the 2016/17 season.
He joined for The Sports last July after four years at Gillingham.
His departure from Priestfield came about after a knee injury forced him to miss a year of football.
Hare, who can play in defence or midfield and is the son of Darren, had a brief loan spell with the Stones back in January 2013.