After rewatching the series and searching for the novels on the net I saw that the novel series ended in February, but couldn't find anything on how.
(Well "anything" is not quite right as there was a guy in a reddit post who himself heard of a friend of a friend who read the last book, but the only thing that he could tell about the ending was that
Tanukichi manages to turn Anna down without her killing him, SOX manages to defeat the person who is behind everything, but Ayame and Tanukichi doesn't become a couple officially
which was too vague for my taste).
Does anyone has read the novel and can share his knowledge with me?