They want to bush out like mad early on. If you don't keep cutting back the lower branches they'll be happy to sit there like a gnarly little bush and never grow.
Especially in our climate where there isn't enough water for them. They really
like water. Lots of buckets in the shower collecting water for the sakura tree with these water restrictions.
And they don't grow fast to begin with, anyway. Mine is about 6 years old and it is only slightly taller than me, so expect this to be a long-term wee-a-boo project.
They start to blossom about now and continue on until about mid-October, if you're lucky. Then they throw on about twice their weight in huge green leaves until early March, when they start to die off and they look blutig awful. That returns you to the gnarly, leafless brown and burgundy stump and branches for Winter. They're not the most attractive of plants during Winter.
Oh, they also like shaded areas. Sitting them next to larger trees makes them happy, or something, especially when the summer sun hits. I have mine between two Jacarandas and an Alder. The Jacarandas take up the blossoming bit after the cherry stops.