According to wikipedia, the term for falling in love with cartoon characters is Schediaphilia, although it's name-dropped in a casual unsourced way, and also lists Plushophilia as the love of plushies. A generalized category of love for fictional characters doesn't seem to exist, despite its long and glorious history. I would suggest mythophilia (from mythos=fictional), but urbandictionary already has that as the subset of zoophiles that love mythical animals.

Or you could lump it in with soulbonding and call it a day.