(literally) one side / everywhere, all around, the whole area / one viewpoint, one opinion or way of thinking / the front page of a newspaper

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

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

parting, parting ways

the first in grade or rank

one case, one matter

Kyūjitai form of 一体: on earth, the heck, in the world (used for emphasis and to express incredulity)

a complete set of something, a complete suit of clothes