The question has been asked, why do all the Iwako Japanese erasers come in sets of 6?
The master boxes that Iwako ships, contains 60 Japanese erasers. By making the Complete
Series Sets in multiples of 6, the Japanese eraser breakdown works quite nicely for us online retailers to 10 Japanese erasers per style. So we get 6 Complete Series Sets per Iwako master box.
We are talking about Iwako only. Dream/Zensinyoji has recently adopted the 60 Japanese eraser box, but the assortments are not always 10 per style. For example, in the last shipment of the Table Grape Japanese food erasers from Dream/Zensinsyoji, we only got 4 of the Purple Table Grape Clusters and 10 of the Green Table Grape Clusters in the 60 Japanese food erasers in the box. The rest were Light Purple Table Grape Japanese erasers. As you can see, we are out of stock of both the Purple and Green Table Grape Japanese erasers.
The complete series sets are a recently new product offering from Iwako. The older assortments do not have the neat and convenient distribution of 10 erasers per master box. If you go to the Iwako Japan site, you can see on their product page, they have breakdown of how many Japanese erasers of a particular style you get in the master box. It varies from series to series.