school (institution dedicated to teaching and learning)

welcome home (said by a person greeting another coming back home, a stock phrase required by the Japanese etiquette)

(idiomatic) deceased person

before the day is done

today, this day / nowadays

engagement, a promise to marry

someone else's younger sister

sworn younger sister

younger paternal half sister

(archaic, men's speech) an intimate form of address for a female by a male: "my sister"