User blog comment:SpookyBoogie27/Light Novel Spoilers/@comment-94.128.249.84-20130207061722/@comment-1359322-20130207063034

You might as well ask this question to the author since we don't even know if he is going to make Sona fall in love with Issei. And it is quite impossible for Issei to have Sona since Sona wants to marry some smarter than her and isn't interested in someone that isn't. Tsubaki (Sona's Queen) even mentioned that it isn't easy for Sona to fall in love.