This is a story of a boy who challenges free diving. "Free diving" ("skin diving") may remind you of the film [Le Grand Bleu](https://en.wikipedia.org/wiki/The_Big_Blue). It is an extreme sport, and each meter added to its record brings us closer to the sea bed and further from the surface where one can breathe again. In this sense, free diving has a direct connection with death, with which our fight continues, refashioned over time, bit by bit. So, why would one free dive, and risk his life? The answer lies within the mysterious bond between the sea and human kind. And in the fast evolving world of competitive diving, new data emerges that casts light on this bond.

At the age of sixteen Ryo Narushima was a genius and looked to have no trouble of getting into Tokyo University and joining the elite of society. However, that summer something cracked inside Ryo's head. With a small knife he brutally murdered both of his parents only leaving his sister alive and cowering in a corner. It is at this grotesque incident that our story begins. Note: At volume 20, the series changed publishers, which created a restart of the chapter numbers. Starting from chapter 61 in volume 26, the first chapter from when the series returned from a long hiatus, the series has been completely written & drawn by Tanaka Akio. While Hashimoto Izou did write the series in the beginning, he had been doing less and less work starting from volume 4. Tanaka & Hashimoto reached a settlement and Shamo continued.