He was promoted to chief of the sales department.
主任がプロジェクトの進捗を報告した。
The person in charge reported on the project's progress.
Ms. Tanaka will become the section chief starting next month.
The company appointed him as the new chief.
As the team leader, she keeps the team organized.
主任 is a team or unit leader, a lower-ranking supervisory role than 部長.
head of year; year-level coordinator
chief investigator; head of the investigation; lead investigator