Iwako makes theme sets. The Japanese erasers in each Iwako eraser are always available as individual erasers. There is one exception to this rule. Two colors of the sunfish animal erasers in the sea life Iwako eraser set are unique to the set and can not be had separately.
A few blue sunfish animal Japanese erasers do come in the Iwako assorted sea life master box. We sell out of these quickly and are out of stock most of the time.