Kosei Akiyama was a child prodigy. At one year old he could do handstands. In fourth grade he hit home runs off middle schoolers. By sixth grade he solved high-school-level math and beat older kids in soccer. Certain he could conquer any field, he chose Go as the arena where he would make his name. He found a local Go salon and sat down across from a quiet fourth grader named Midori Enomoto. Kosei lost. He studied ten hours a day for three months, accepted ever-larger handicap stones, and still lost every game: zero wins, one thousand losses against five children his own age or younger. For the first time, effort meant nothing. He quit, and the rest of his talents faded too. Kosei drifted into a gray high school life, no longer a genius, no longer anything.

Then, at a town festival, he filled in as a cafe helper. The sound of Go stones drew him to a booth where a former insei named Kogane Shirayama was running a challenge match. Kogane talked big about his own defeats and his resolve to claw his way back to professional play. Kosei, who had not touched a board in years, sat down expecting to lose. He won easily. Confused, he learned that Kogane was barely stronger than an amateur. Just then a news alert flashed: fourteen-year-old Midori Enomoto, the same girl who had crushed him at the salon, had just become the youngest-ever challenger for the Judan title. Kosei understood at last. The salon where he had trained was not a normal place. It was a well deeper than the ocean — a room that held five prodigies on the scale of a Shohei Ohtani. He had not been mediocre. His opponents had been freaks. He dragged Kogane back to that salon, face burning, and demanded to know where the five were.

Kosei Akiyama is the protagonist: desperate for validation, humbled by a defeat that was never his fault, and now burning to reclaim the invincibility he once took for granted. The five geniuses are his foils and his goals. Midori Enomoto, a silent, near-expressionless middle schooler, is already a professional and the media's chosen successor to the great Go champions. Hazuki Ichihara, a high school influencer with millions of followers, uses her charm to popularize the game but hides a sharp, cutting nature behind her public smile. Koshiro Kiryu, a towering third-year whose family runs a corporate empire, is forbidden from pursuing Go professionally; he dominates high-school Go as his only permitted arena and nurses a buried frustration. The remaining two include an older girl named Kan Okuno, who worked at the salon and carries her own enigmatic past, and a fifth prodigy introduced later as the story progresses. Around them moves Tenmu Yotsumura, a calm eight-dan who runs the salon "Nezumi," and Keishu Amahara, the current holder of all seven major titles, who watches Kosei's rise with knowing interest.

The story follows Kosei as he re-enters the Go world step by step. After defeating Hazuki with a handicap, he enrolls in the Go club to reach Koshiro. The club's team tournament forces him to confront not only his second target but also the painful reality that Koshiro may quit the game entirely due to family pressure. Their match becomes a clash of twisted dreams — Koshiro projects his own abandoned ambition onto Kosei, and Kosei must articulate what he himself truly wants. He wins, but the victory is complicated. He then meets the third prodigy, a child named Itsuka Mikuriya, in an impromptu game that tests whether his growth is real. The arc pushes Kosei toward the next threshold: the professional qualifying exam. There he faces Kogane, who has trained alongside him, and a field of desperate competitors. Only two of them will earn a pro license. The exam becomes a year-long war of endurance, technique, and self-knowledge, with each opponent carrying their own reason for wanting to cross the same narrow gate.