Undocumented mark that's comprised of the symbol 'Hira 平 under a Roof'.

The stamp that was used to mark this float had an unusual 5-sided pentagon outline shape.  Using the pentagon shaped to form the outside of the stamp conveniently made the roof lines parallel to the outside edge of the stamp.

This is an extremely rare mark.  It's the only example of this mark known to exist in collections.

The float itself measures 33 1/2 inches in circumference or about 11 inches in diameter.