Some back-story. It seems that both Itsuki and Isurugi have deep roots in that town. And Azumi too, for that...
Kanade
Just what is Isurugi anyway? Or for that matter, Kanade? https://reader.vortex-scans.com/read/kanade/en/5/23/page/1
A guy has got to keep his promises . . . even if it takes a few hundred years. https://reader.vortex-scans.com/read/kanade/en/5/22/page/1
