Short for 郵便私書箱 (yūbin shishobako, “post office box”) (box hired as collection point for mail)

a letter, epistle (written message or note) / (archaic) a utility paper used for various purposes, such as for jotting down notes or for wrapping items

(Kagoshima dialect) a letter, epistle (written message or note)

to reach

(archaic) Alternative form of 届く (todoku)

(archaic) Alternative form of 届ける (todokeru)

(chiefly women's speech) first person singular pronoun: I, me

(polite) first-person singular pronoun: I, me

a personal or private matter / (by extension) selfishness

(formal) first-person singular pronoun: I, me