There isn't a real solid answer to why taiyaki was specifically chosen as a fish there been snacks similar in the Edo period but they also weren't just fish. But if I got this right Seijiro Kobe was the originator of taiyaki. He was looking for away to package his red bean cakes so they would sell better. They are really good especially with some ice cream. If you never had red bean paste inwould say it have a coco flavor to it not quite like chocolate but similar!