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

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

deathwatch beetle

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

You should treasure every encounter, for it will never recur.

vicissitudes, the way that the world or a person prospers one day and declines the next

dotting the i's and crossing the t's

successive series of questions and responses

a kunoichi (female ninja) / Synonym of 女 (onna, “woman”)

a handful