I suspect the author wanted to write more but wasn't allowed to. Still, we got a proper closure for this series. I don't know if this is popular enough for JNC to consider licensing, especially with a completed fan translation, but one can always hope.
I know it's been a few years since this was suggested, but I want to re-suggest it... or refresh the suggestion or... well, I'd like to see someone license and produce this one. There was clearly more to the story after the anime ended. The manga was axed but the LN kept going and seemed pretty good from the few spoilers I've seen. If the spoilers are any indication, the story doesn't turn out to be the typical shonen storyline.
I would have a little more hope now about this series being picked up by someone after seeing old series such as Dxd and DaL being taken by Yen Press and this series has just had a spin off staeted in the last few years so is still active. But does it have the same fan base as those two? Probably not, but it is a series with a happy end which I would love to read fully. I have the series only up to 15 in Japanese so I would be happy to fi ish the collection twice in both languages