投とう書しょ箱ばこMeaningsNoun1. suggestion box; complaints boxKanji used投throw書write箱boxComposed of投とう書しょletter (e.g. of complaint); letter to the editor; letter from a reader; contribution (to a newspaper, magazine, etc.)Noun箱はこbox; case; chest; package; pack; crate; car (of a train, etc.); shamisen case; shamisen; counter for boxes (or boxed objects)Noun