I appreciate your comment, and the additional connections you provided. Danke! Gave me something new to consider.
I’ve always let this coin off easy, thinking that most of its problem was a cross-cultural misreading of its Phoenix device, in much of the West an allegory for rebirth, return, resurrection—all somewhat touchy assertions for a Japan so early into the postwar.
But then you rightly point out the Sunburst at the center of the 1957-58 100-yen’s “British florin reverse.” And looking at it fresh, suddenly I’m thinking “Sunburst—emblematic of the Emperor’s divinity?” Yikes! No wonder this coin had problems.
I was less convinced with your “ornamental” precursor as exemplified by the 1933-38 5-sen piece; for me the 1933-38 5-sen design wasn’t ornamental so much as is was purposefully symbolic, with a modern take—the (stylized) 8-lobed frame makes the center-hole into the “Sacred Mirror.”
But then I took a closer look at the 100-yen and its cherry blossom wreath: I’ll be darned if you can’t see an 8-lobed surround that can easily be seen as the frame of the “Sacred Mirror.” The Sun Goddess and the Emperor’s divinity yet again? Again, yikes!
All this, and only a bare decade since the Emperor was widely (although perhaps not correctly) understood to have renounced his divinity? Smacks of Revisionism with a capital R!
It may be the story of the Japanese 1957-58 100-yen having been inspired by the contemporary British florin was more cover story than anything else, invented and propagated to either disguise an effort to (symbolically) restate the imperative for Emperor-worship, or else—more charitably—design elements of Japanese coinage past were incompetently fitted into a borrowed British template.
Fun stuff, speculating….
But truly, thanks for cluing me into how outrageous the ’57-8 100-yen really was. No wonder it had to go.

v.