"regarding romance or other such mechanics"
Mechanics like Persona5 or Dragon Age? NO. The Romance your Hero gets depends on the Outcome of the War. Period. Only If you get the neutral/good ending; there is a chance to romance two characters insted of one. It depends on your actions aka "trust mechanic". Hakan and Witer can be invited to the bathhouse later... ... Maybe you get a chance to smoosh them.
Here is the link for the "BEST good/neutral ending":
(Spoiler)