Property tax

I am building a home here on land jointly owned by my wife (Japanese citizen) at a 50:50 recorded proportion (land only).

After the house is built, I assume it will be jointly owned.

If I were to die, I read that she will inherit half of my assets and then my children (two of them -- both U.S. citizens here with proper visa, one married to Japanese citizen) will get equal shares, and that inheritance tax for them can be substantial.