Does the series really end with just the 28th book????

I can tell Ты that the Манга doesn´t end in the 28th book. It´s just that they're coming out really late and i don´t know why, but don´t worry it doesn´t end like this. But Ты can read the Манга in mangareader.net they come out sonner them mangafox.
Hope this helped :)

Don't worry, it ends at the 30th book in most of the Манга website. For the final, Ты can go on YouTube but they haven't translated the last chapter yet.
I hope this helped you.