It gets you in the chest with the smallest possible crime: a kid breaks the leaf fossil his dad loved, says nothing, and then has to keep living in the same house as that silence. Rintarou's guilt is the whole engine here, and the film is patient enough to let it just sit there, unconfessed, while he goes back to the riverbank to dig like he can find a replacement in the dirt. Then Toshi shows up, strange and unexplained, and the movie never over-explains him either. This is Touko Yatabe's graduation work out of Musashino Art University, so it has that student-film honesty where nothing is loud and nothing is padded. The stratum metaphor lands because it's earned: layers pressing down, memory turning into stone. Slept on, and it deserves better than that.
Rintarou carries a secret that weighs on him: he's broken his father's cherished fossil and can't bring himself to confess. The guilt gnaws at him as summer stretches ahead, heavy and uncertain. One afternoon at the riverbank where he usually digs for fossils, he encounters Toshi, a boy who seems to exist slightly outside the ordinary world. Something about him feels different, untethered from the normal rules of things. What begins as a chance meeting becomes something more as the two spend their days uncovering layers of earth and stone together. Toshi moves through the world with an ease that both puzzles and comforts Rintarou, and slowly the summer takes on a dreamlike quality. Between the striated dirt and the gentle rhythm of their searches, something shifts. The guilt that once felt suffocating begins to transform into something else: understanding, acceptance, maybe even peace. This quiet film traces how small moments and unlikely friendships can rewrite the stories we tell ourselves about failure and forgiveness.