With Monday marking the third anniversary of Russia's full-scale invasion of Ukraine, a book for junior high school students in Japan is gaining attention for explaining why wars occur in an easy-to-understand way with manga and other illustrations.

The book, titled "Bokura wa Senso wo Shiranai" (We Don't Know Wars), was released for libraries last year by publishing company Gakken.

Under the supervision of Yu Koizumi, associate professor at the University of Tokyo's Research Center for Advanced Science and Technology, who specializes in Russia's military policy, the 136-page book explains what wars are and why they occur, using Russia's invasion of Ukraine as an example.