I also agree with Tony that there's a very high chance that it's a male, and while this would bum most people out, I am glad to hear that you are happy that it's a male and that you have already set up an arranged marriage with a "hi u"
!
While sexing young tosai can be very tricky, I believe that the Japanese breeders and experienced hobbyists know how to do it. That's why most tosai are males as it is believed that they have less show potentials than females. This is why I have shied away from buying tosai altogether because, while there have been many debates about males and their comparisons to females, most, if not all, GC show winners are females.
Anyways, good luck with your Omosako shiro and his (or her) development.