After the completion of the probationary period without discharge, such teachers as are thereupon reemployed shall continue in service in the public schools during good behavior and competent service and prior to the age at which the teachers are eligible for retirement, pursuant to section 88-73 or 88-281, and shall not be discharged or demoted except for one or more of the causes specified in section 302A-609.
HRS § 302A-608