Matz is neither a common german name (I've never encountered it) nor is class "klass" in german. It's "Klasse". Maybe you just missed out an "e" on the name asw

Matz is neither a common german name (I've never encountered it) nor is class "klass" in german. It's "Klasse". Maybe you just missed out an "e" on the name aswell? There is "Matze" which would be a short version of "Mathias".