<Window x:Class="Window.Konnichiwa"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="こんにちは、GUI！" Width="100" Height="75" WindowStartupLocation="CenterScreen" WindowStyle="ToolWindow">
</Window>