Tsuyoshi, a classmate of Taichi, forms part of a tight-knit group alongside Jirou, Yoshio, and Taichi’s younger sister Misako. Initially, the children immerse themselves in militaristic role-play, mirroring the nationalist propaganda pervasive throughout the war. Their lives shatter when firebombs ravage their town, obliterating homes and schools. Driven to scavenge and steal for survival, they seek refuge in a cave dubbed their “secret fort.”

Subsequent raids orphan them all, leaving each bearing physical and emotional wounds. Tsuyoshi, like the others, slowly succumbs to festering injuries and starvation. After Misako perishes, he follows shortly after, another casualty of their ravaged world. In a fleeting surreal interlude, their spirits converge near a symbolic tree sprouted from Haruo’s final gesture—planting a cake fragment—before Tsuyoshi’s existence dissolves entirely.