@miyako19: I did say 10 years.
Whether there's a romance or not, he'll be in a dilemma either way.
If she's got a crush on him, scary dad is scary about "u seducing my daughter!?"
If it's more familial feeling, scary dad is scary about "u trying to replace me as her dad figure!?"
If she call him 'onii-chan', hello FBI.
There's no easy way out of this one.