层间声音

Anoiseiscomingfromthefloorupstairs.Eunsu,hearsthisforoveramonthwhichcausesuncontrollableangertoriseup.Shegetseliminatedagainfromacompetitionshehadpreparedforalongtime.Eunsudecidestowriteherlastpiecewiththethemeofthenoisebetweenthefloorsandpersuadesherfriendtohelpherfollowandtrackthesecret.