What makes an anime a romantic anime?

When you say that an anime is a romantic anime, how romantic must it be?

If an anime's two main characters get together in the end, is that a romantic anime? Even if the whole anime was about something else?

I don't think the above counts, but I remember someone putting InuYasha as a romantic anime... but I think differently.

So would someone please tell me how much romance is in an anime with 'romance' as one of it's genres