>>2307383http://www.redbubble.com/people/nuriox/works/10785467-anime-watamote-spark-shirt?p=t-shirtSomeone linked it in the last thread as well. That's how I found out.
They don't have the exact color scheme Tomoko wears but it's close enough.
Warning now: price may be a bit much but I couldn't help myself...