The name may be familiar to those who frequent seafood restaurants, as these tiny cephalopods are served as a delicacy up and down the country. But Toyama is the only place in the world where it is possible to see them in their full shining glory. And it's not every day of the year that you can pop on down to the beach to see them - hotaruika live out most of their year-long lifespan in the deeps of the sea of Japan, and only come to the shallows to spawn in spring (March-June).
Even then, seeing squidly bioluminecence on your own would be an extremely rare occurence - a whole list of conditions need to be met, such as it being a clear night with a new moon, and it not having rained the day before. The most impressive sight, of the whole beach glowing blue, is the result of a hotaruika stranding, when they are thought to lose their ability to navigate by moonlight and get washed up on the beach by the thousands.
The second most thrilling way to experience the beauty of hotaruika is to go fishing for them - you can go on a tour on one of the fishing ships that head out to sea in the wee hours of the morning, and scoop up boatloads of squid destined for the kitchen. These tours run out of Namerikawa, a small town just outside Toyama city and smack in the middle of firefly squid zone. The squid tend to light up when stressed - it serves as a defence mechanism - so when they find themselves trapped in a massive net and lifted out of the water, it makes for a jaw-dropping sight.
If you're the less adventurous type, or simply want a bit more certainty about what you're going to see before you book your Shinkansen to Toyama, there is also the Hotaruika Museum, also in Namerikawa and a stone's throw away from the water. The live squid there is collected on the very same fishing tours mentioned above by museum staff, and you can have an 'abridged' version of the fishing experience with their bioluminescence live show. Apart from that, there are also plenty of family-friendly educational exhibits that will bring you up to speed on the anatomy and life cycle of the hotaruika, as well as many more species of sea life found in Toyama Bay. There is even a 'petting aquarium' where you can get up close and personal with the little squid. As you might expect, though, the squid are a seasonal display - outside of the spring months you will be treated to bioluminescent plankton instead.
After you've been thoroughly educated on the live squid, perhaps it's time to get acquainted with them in edible form - the attached cafe serves, as you might expect, firefly squid in the form of fritters or a burger. For the more traditionally inclined, there is also an array of stalls selling squid marinated in every imaginable way - with free tasters for everything!
If you're heading towards Toyama, or even Kanazawa (a bit over an hour away on the local train), I'd highly recommend this as a side trip - and an unforgettable experience.