assistant section manager; assistant section chief
A specific corporate title in Japanese companies, ranking just below 課長 (section manager/chief).
He was promoted to assistant section manager this year.
As an assistant section chief, I am in charge of preparing meetings.
課長 is the section manager/chief, one rank above 課長補佐.
部長 is a department manager, typically a higher rank than 課長.
Compound of 課長 (section manager) and 補佐 (assistant, aide).