 Gjems-Onstad had served with Manus in the Norwegian Home Guard after the war, and had met his later wife Tikken Manus for the first time in 1943 when she worked as a military attaché in Stockholm.The three remained lifetime close friends ever since they met during the war.In 1961 Gjems-Onstad left his lawyer's firm to work as a consultant in Den norske Creditbank.