・きみが昨日無くした戸棚のカギ
・真夜中の教室へ忍び込むためのカギ
・未解決事件のカギ
・隣のあいつの口を閉じるカギ
・死人の目をこじ開けるカギ

・The key to your closet you lost the other day
・The key for sneaking into your classroom in the dead of night
・The key to crack unsolved cases
・The key to lock the mouth of that fella next to you
・The key to force open a dead man's eyes