How you'd normally say I love you (romantically) would be daisuki. If you want to be grammatically correct, "Watashi wa <person's name> ga daisuki desu" or short form would probably work with "<person's name> ga daisuki da" you could use anata or omae for the person's name if you want to, but Japanese people don't ordinarily use 'you' in conversation, they ordinarily just use the person's name. Oh, but make sure you add -san or -kun (for a boy) or -chan (for a girl) or its not polite. ... I'll not go into the other different things you can add to people's names here, as you then have to get into the Japanese social ranking system, which seems to be pretty complex. Anyhow, hope that helps. And nifty tattoo by the way. I had a friend once who got a tattoo that the guy said meant 'immortal', but actually meant 'monkey.' Poor guy. Good thing you didn't fall into that trap!