I don't know why people think that it was axed, the series just ended.
That's mostly because of lines like Koume crying after failing rank 3 exam and other stuff, it felt like there were stories the author wanted to tell but didn't get the chance. Also the fact the sales of the anime were really bad made people think the manga was cut short because it wasn't liked, which is wrong of course, there are a lot of manga fans still active online on multiple sites, regardless of the anime popularity.
Honestly I found the ending a bit disappointing. Not a big fan of them becoming rank 1 after learning the truth. Would've preferred them just telling the god to fuck off and figuring out their own way to lift the curse
The author notes at the end say that the god isn't a villain.
The point is that Chiya and Kon accomplished what their parents couldn't. First of all Tokie couldn't express her feelings for Yami, so she couldn't become Rank 1 and that's when Kurou entered and the story started, Kon is different to her mom and that's why she can stand beside Chiya now.
Then Yami gave up herself to fate, she explains it herself, Chiya is different to her because she can decide her own future, it isn't set in stone and anything can happen, not even the god knows, that's why they are Rank 1, to prove a point: they can be Rank 1 without giving themselves to the town.
That was the climax of volume 5:
That and Chiya's name, were foreshadowing to what was gonna be reiterated again in these last chapters:
That's what Chiya and Kon did to change fate and stay together.