Manga by Girls and Panzer Project and Ryohichi Saitaniya.
"Senshadou" is a traditional sport using World War II era tanks in elimination-based matches. Widely practiced by women and girls alike, it's advertised as a form of art geared towards making ladies more prominent in culture and appealing to men. Becoming a worldwide phenomenon over time, the influence of senshadou leads to the creation of a world championship which will soon be held in Japan.
