I think you mean that Prunus serrulata does produce fruits? What I meant was if your tree doesn't produce fruits, then it would be an ornamental variety which doesn't produce fruits as many are sterile. Some may produce a few. I can't even say for sure that your tree is Prunus serrulata, I was giving an example of a tree which looks similar.
Fruit: Typically no fruit since the 'Kwanzan' variety is sterile, the species P. serrulata produces a small red cherry.