Randoseru are the leather backpacks elementary school children wear.
They’re expensive and often handmade – price tags average around 35,000 yen
They’ve been an essential item for elementary schoolers for over 50 years.
They’re sturdy and high quality; they often survive relatively unscathed throughout the whole 6 years of elementary school.
For some etymology of the word randoseru and background info… check out the Japan times Q&A.