YES, you do.
Ritsumeikan University requires all study abroad programs to be covered by comprehensive travel insurance as specified by the University for risk management purposes. In addition to the Overseas Student Health Cover (OSHC), students travelling to the ANU are also required to purchase RU designated Travel Insurance.
OSHC is mandatory for all students by the Australian Government and is required when applying for a student visa, while RU designated Travel Insurance covers other incidents/accidents/liabilities not covered by OSHC (with some exceptions) and is required by RU to minimize your risks.