(a) Notwithstanding any other law, after a tenant has continuously and lawfully occupied a residential real property for 12 months, the owner of the residential real property shall not terminate the tenancy without just cause, which shall be stated in the written notice to terminate tenancy. If any additional adult tenants are added to the lease before an existing tenant has continuously and lawfully occupied the residential real property for 24 months, then this subdivision shall only apply if either