A state judge Monday dismissed a misdemeanor tampering charge against Myron B. Thompson Academy Principal Diana Oshiro, three months early.

Oshiro, 67, pleaded no contest in June to accusations that she authorized and backdated leave authorization forms for her sister, elementary school administrator Kurumi Kaapana-Aki. Instead of being sentenced, Oshiro was given the opportunity to avoid conviction by submitting to probationlike court supervision for a year.

The charge was to be dropped if she stayed out of trouble for that year.

Circuit Judge Dean Ochiai granted Oshiro’s request to terminate her court supervision ahead of schedule and dismissed the tampering charge.

Deputy Attorney General Vince Kanemoto did not oppose Oshiro’s request for early dismissal, adding that she had completed all that the court required of her, including performing 40 hours of community serv­ice and writing a letter of apology to the governing board of the public charter school.

Kaapana-Aki had pleaded no contest to tampering and felony theft. She has to complete five years of probationlike court supervision before she can have the charges dismissed but can ask for early dismissal after 2-1/2 years.

She was accused of working at her other job as a Hawaiian Airlines flight attendant while on the clock and getting paid for her elementary administrator position.