superintendent supervisor; assistant commissioner
A high rank in the Japanese police, above chief superintendent and below superintendent general. Equivalent to assistant commissioner in some English-speaking forces.
He was promoted to superintendent supervisor.
Superintendent supervisor is an important post in the National Police Agency.
警視長 is a lower rank (chief superintendent), below 警視監.
Compound of 警視 (police inspector) and 監 (supervisor, overseer). The term is a modern creation for the Japanese police rank system.