When you think about it, the realm of sake flavor profiles and types can be perceived as, well, a bit narrow. From the sweetest to the driest, from the roughest to the cleanest, we are not exactly talking about major bandwidth.
This, in fact, can be the appeal of sake. Within that narrow range are deep but subtle facets to be explored. But still, the range of types and styles is indeed a bit different. It takes a geek (like me) to fully appreciate them. "This one is made with rice polished a full 5 percent more than that one. Whoa! BIG difference!" Nah. Not really.
And so it was that, in 1970, a group of Niigata brewers got together and thought, "Hey, can't we come up with something really different, but still have it recognized as decent sake?" The result was akaisake.