Hi Don,
These extravagant helmets were/are called kawari kabuto: extraordinary or fantastic helmet. While armour never became an item of dress, courtly or otherwise, in Japan to the extent that it had in Europe, the emergence of increasingly well-armed -- and armoured! -- feudal armies forced the nobility, the great warlords and generals, to seek professional and socio-military "distance" on the battlefield. This was visually accomplished primarily by means of the kabuto.
Kawari-kabuto, as headgear, are unique in the history of warfare. In Europe, the ornately crested and mantled helm was commonplace, even de rigeur, on the tournament field, but it is open to speculation to what degree, if any, it was worn on the battlefield. Its purpose can arguably be said to have been largely decorative, with shield and horse mantling being the primary "identifiers" or heraldic "calling cards". On the other hand, in Japan, whereas entire armies might be outfitted in the same style and colour of armour sporting the same flags and other means of identification, the helmets of the great warlords were their primary means to announce to the opponent who they would be facing. As one Japanese scholar asserts, the "kawari kabuto were made with the idea of calling attention to the existence of one person: the wearer." (Sasama) Finally, as with the finest Kostümharnisches in Europe, it was a very obvious expression of status and wealth.
The figure to the left is that of Katō Yoshiaki, no relation to, but a contemporary and associate of Katō Kiyomasa. They were two of the “Seven Spears (shichi hon yari) of Shizugatake”, who distinguished themselves at that battle in 1583. He is wearing his "trade-mark" silver-leafed Fuji-san kabuto (as the descriptive suggests, it represents Mt. Fuji), remarkable not only for its size and striking design, but for the unique modeled queue that served as a rear crest (ushirodate) on the helmet.
To the right of Katō is Maeda Toshiie. His kabuto is generally accepted to be of the namazubi family of kawari kabuto, representing stylized catfish tails, a trademark of the Maeda. While I personally agree with this classification, recent research suggests that they may actually belong to another stylistic group. Another trademark of the Maeda is that their helmets were usually, though not always, leafed in precious metal.
I am very excited about the re-release of both of these pieces; but especially of Katō Yoshiaki, and very much look forward to it landing on these shores.
Augie