St. Andrew's Priory School is launching a search for a new head of school in the wake of the departure of Marilyn Ma-tsunaga after two years in which she saw enrollment grow and financial operations improve.

Matsunaga resigned effective Jan. 17, said Ivan M. Lui-Kwan, chairman of the school's board of trustees.

Lui-Kwan said Matsunaga told the board she felt she had completed the tasks she set forth when she was hired and wanted to move on to other challenges.

He said Matsunaga was hired to write a business profile as well as enhance the financial operations of the school and had done both.

She felt it was "time to move on to new challenges. ... She's been thinking of it for a while," Lui-Kwan said.

Matsunaga could not be reached for comment.

"I think the board is happy with the fact that the financial operations have been improved," said Lui-Kwan. Increasing enrollment at the school, which now has about 550 students, was a large part of that success, he said. Lui-Kwan said that amounted to an increase of about 50 students.

Lui-Kwan has appointed two board members to head a search for a new leader, but in the meantime he is spending about five hours a day at the school to make sure there's a smooth transition. He expects an interim head of school to be appointed by the end of this school year.

However, trustees are also looking at a new organizational structure for the school, and another committee is investigating whether changes should be made to that.

"We'll look at different models to see which model might work best for our school," Lui-Kwan said.

Educators say it's not unusual for a school leader to leave partway through a year. Lui-Kwan said Matsunaga "did not want to disrupt" the school with her departure just before the holidays.

"There will be no disruption and things will move forward," said Lui-Kwan.

A letter is being drafted that will go to parents in the next few days, but teachers and staff have been informed, he said.

Matsunaga was originally hired in July 2004. Under former Gov. Ben Cayetano, she directed the Hawai'i State Health Planning and Development Agency and then headed her own consulting firm for healthcare development. She has a master's degree in business administration.

Reach Beverly Creamer at bcreamer@honoluluadvertiser.com.