Charman brings a wealth of experience to the Hillians, having recently played for Bognor Regis and Eastbourne Borough, in the National League South.
Chapman told the club's website: “With pre-season just around the corner, I am delighted to confirm both Gary and Kieron.
"Gary is a player I’ve always liked, and will bring vast experience and quality to our squad. He can play in a number of positions, and I’m looking forward to working with him. Kieron’s situation was brought to my attention whilst I was away! I’m extremely pleased to have secured his signature.
"He’s a skillful player, who has a great eye for goal.” Chapman continued, “I feel we have recruited well over the break, and are still looking to bring in a few more over pre-season.”