Authored by , the manga was first serialized in the magazine Comic MILF between 2022 and 2023. It is praised for its detailed artwork and its ability to capture the sweltering, nostalgic atmosphere of a Japanese summer. The OVA (Original Video Animation)

As they lounged by the river, soaking up the sun's rays, Kaito couldn't help but feel a sense of restlessness. He had always been passionate about swimming, and with the summer break stretching out before him, he was determined to make the most of it. The others shared his enthusiasm, and soon they found themselves planning a series of impromptu swimming trips to the nearby beaches.

Carl Jung wrote of the puer aeternus (eternal boy). Japanese culture, with its intense academic pressure from September onward, makes August a liminal space. The shounen knows that when summer ends, so does the allowance for being childish.

"Shounen ga Otona ni Natta Natsu: Free! Free!" is a Japanese phrase that translates to "The Summer of Boys Becoming Adults: Free! Free!" or more accurately, "The Summer When the Boys Became Adults: Free! Free!". However, it seems there might be some confusion with the title, as "Free! Free!" doesn't directly relate to a widely known work with this exact title.

We must acknowledge the shadow of this phrase. Not all summers are idyllic. For many boys, becoming a man in summer involves trauma.