(1) The vulnerable youth guardianship terminates on the vulnerable youth's twenty-first birthday.

(2) The vulnerable youth may request the termination of the vulnerable youth guardianship at any time. The court shall terminate the vulnerable youth guardianship upon the request of the vulnerable youth. The vulnerable youth may also withdraw consent to the vulnerable youth guardianship at any time.

(3) The guardian may request termination of the vulnerable youth guardianship by filing a petition and supporting affidavit alleging a substantial change has occurred in the circumstances of the vulnerable youth or the guardian and that the termination is necessary to serve the best interests of the vulnerable youth. The petition and affidavit must be served on both parties to the vulnerable youth guardianship.

(4) Except as provided in subsection (2) of this section, the court shall not terminate a vulnerable youth guardianship unless it finds, upon the basis of facts that have arisen since the vulnerable youth guardianship was established or that were unknown to the court at the time the vulnerable youth guardianship was established, that a substantial change has occurred in the circumstances of the vulnerable youth or the guardian and that termination of the vulnerable youth guardianship is necessary to serve the best interests of the vulnerable youth. The effect of a guardian's duties while serving in the military potentially impacting vulnerable youth guardianship functions is not, by itself, a substantial change of circumstances justifying termination of a vulnerable youth guardianship.