La historia transcurre 3 años antes de los sucesos de Girls und Panzer. Tras pensar mucho el MEXT decide traer a 16 jóvenes de Europa y América para probar la valía de los varones en dicho deporte. Sherlock , Archiduque de Austria, es enviado por error a la Escuela de Pravda en donde tendrá que afrontar las adversidades que el destino le tiene preparado

Y/N, a young ordinary student who always dreamed of participating in the tank warfare sport called Sensha-dō. Although Sensha-dō sport was only meant for girls, hence his dream will never come true. But, it all changed when he and his friend Ross found an old rusted Renault R35 inside an abandoned barn. Although it may look like trash in Sensha-dō, but not in Tankathalon. Tankathalon, unauthorized tank matches organized by tank crews themselves. In short, there is only one rule; tanks must not exceed at least ten-tons, anything else might happen. Tanks may intrude in the middle of a match, start a wildfire, betray your companion, and lastly, a battle royale might happen. Along the way, he will meet such an extraordinary girl named Marie. She will be his instructor for his French tank. They will fight together, climbing at the top of the Tankathalon Championship. This is a Reader X Marie story, I do not own Girls und Panzer and any images that I'll be using, thus they all belong to their respective owners.