successive series of questions and responses

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

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

(education) second year in senior high school; eleventh grade / (education) second-year student in senior high school

(shogi) two pawns on a same file (an illegal move)

the second dimension / (by extension, Internet slang) the 2D (i.e. anime, manga, video games, etc.) world; the fictional world

A city in Iwate Prefecture, Japan, Asia / A district of Iwate Prefecture, Japan, Asia

number two / runner-up

(Internet slang) opening 2 different windows (chatroom, etc.) at the same time