The "randoseru" rigid backpack is an iconic item for Japanese schoolchildren.

But after they have been toted to and from home through all six years of elementary school, families often don't know what to do with them. They become obsolete after elementary school, and many parents say they can't throw them away because they hold so many memories of their children's younger days.

Other than stowing them forever in the back of a closet, Toshimasa Masuda offers another solution: Turn it into a miniature randoseru.