knowledge of a subject

secret police

format, book size / size of a sheet of paper used for ukiyoe

the situation reverses itself; the tables are turned; the shoe is on the other foot

diatom

meter; gauge

cry of a cock, or the resemblance of; cockcrowing / time of first cockcrowing, at around 2:00 am / (figuratively) dawn, daybreak

prefectural police

mobile phone that is contracted in the name of non actual owner and commonly used for fraud

(linguistics) word form primarily used in spoken language