<Window x:Class="Window.Konnichiwa"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Doukaku" Width="100" Height="75" WindowStartupLocation="CenterScreen" WindowStyle="ToolWindow">
  <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
    <TextBlock FontSize="8">こんにちは、GUI！</TextBlock>
  </StackPanel>
</Window>