If you were to take one of those decade long soap operas, pick a random episode, and say this is the start of the story then watch two in universe weeks worth of episodes then say this is the end of story you would get this manga/novel. Just kind of starts randomly then ditches you after it resolves one event.
It had potential that I guess the writer decided would be better to not even try to realize. Not surprised this sequel bait turned into nothing. If I was a novel reader I would never read anything written by them again. Would never be able to trust them to not just abandon their next story again.