Board Thread:News and Announcements/@comment-9410476-20190411063651/@comment-2600:1702:3EC0:4B80:A1FC:3A0C:933D:AA58-20190417062324

Mothy's tweet suggests it's after the novel Master of the Heavenly Yard but before Banica Concerto. So, during the in-between period where the souls were still reincarnating into the Fourth Period.