This work kit was developed for the 6th annual "Karakuri Puzzle in Hakone"in 2016. "Itokomabako" was made in Hakone during the Edo period and used by Shamisen players as a box to put strings and bridges in. We do not know many things about it, so it is a mysterious box. There are two drawers. When you open the one drawer, the other drawer opens at the same time. When you close the inner drawer, the other drawer closes at the same time.