A group of onmitsu, government-employed undercover agents, established by the 8th Tokugawa shogun, Tokugawa Yoshimune (1684–1751). Sometimes described as ninja.

a special talent or skill that one is good at / an act or expression that one often does

first storm of spring

(2channel slang) repeating something for the n-th time

deathwatch beetle

(Buddhism) think on the power of Kannon

(idiomatic, proverb) be quick on the uptake, understand the whole situation from just a few clues

one-hundred fires and one-hundred hits: making the mark every time

(figuratively) a narrow world view based on limited experience

an ordinary person cannot understand the ambitions of a great man