Normally, after you've met a person at least twice you can select to say they're fantastic. They won't receive this rating until the next time you meet, which means that nobody should be able to say I'm fantastic until we've met at least 3 times.
However, there have been Miis that have said I'm fantastic on the second time we meet and today one said it when we've never met before. How can this happen?
Best Answer
Did you find those Miis from SpotPass and not classic StreetPass? Because in an hotspot you can receive people's Mii but that person may not "meet" your Mii at the same time. I know this because a friend of mine has met my Mii through SpotPass but I haven't met his one that day.
Probably that person have met you more than 3 times (giving you the "Fantastic"), and the first time you've received its Mii in your Plaza you've actually got the "Fantastic".