through the series, we have learned that zanpaktou are sentient spirits within soul slayers. each has a different personality as well as a different form ranging from, personality wise, quiet, conceited, lazy, prideful and form wise, monkey with a snake tail, a person, etc.
now to tap the strength of your zanpaktou, you need to first develop a relationship with it (most importantly through bankai). ichigo seems to have a master-student relationship (at least with zangetsu). now if ichigo is able to do that - could a shinigami develop romantic feelings for one's zanpaktou? if one can care for a zanpaktou, could one possibly fall in love with their zanpaktou's inner spirit?
i know it sounds weird - what do you guys think?