Irrelevant little gripe:
The Drone Beetle/Gold Beetle panel is a bit weird, since "Gold Beetle" likely refers to the Chrysina resplendens/Plusiotis resplendens, or Jewel Scarab, based on how it is designed. "Gold Beetle" as a phrase generally is more likely to refer to the Charidotella sexpunctata, or Golden Tortoise Beetle, which looks nothing like a Drone Beetle and isn't even in the ballpark of the same size, as it is the size of a ladybug.
None of this matters, of course, but it's something interesting.
Furthermore, this gets even stranger since it's apparent that Nairo couldn't have caught the "Gold Beetle" out in the wild considering that both the Golden Tortoise Beetle and Jewel Scarab aren't native to Japan but instead to the Americas (commonly, Costa Rica for the Jewel Scarab). This indicates to me either that the author isn't brushed up on his bugs, doesn't really care, or there's something weird going on on the T/L side of things.
But again, it doesn't really matter and I'm not bothered by it, I just thought it was odd.