Addendum: “yume” is Japanese for “dream”. They dream of being in a (relation)ship with the other person. We used to call that “self-ship”, I’m pretty sure (“I ship myself with xyz”) but maybe the difference is that this is not about a character but a real person? Which would make it real person shipping which I think most people agree is a dubious pastime. Did I just argue myself into saying having a crush is problematic? I need sleep.