He attended school in Auckland, New Zealand, then shifted to the Cook Islands as a student at Avarua Primary school, Avatea Primary school and Tereora College.
Afte rplaying rugby league at a national level, he studied at the University of Canterbury in Christchurch, New Zealand, graduating with a Bachelor of Engineering. After a career as a public servant, culminating in serving as Secretary of Works between 2003 and 2008, Herman was elected to the seat of Ngatangiia at the 2010 election. In May 2011 he was made associate minister for the environment.
Herman was invested with the traditional Teaia Mataiapo title in 2009.
He is a member of the Cook Islands Party.