Okamoto predicted a home run to the Koshien backscreen in 2014, then hit it in his first game. He says his coach made him say it

Kazuma Okamoto became Chiben Gakuen's cleanup hitter in Nara in the autumn of his first year, and web Sportiva's Shiro Tanigami counts 73 home runs across high school, 48 in his second year. Writer Kentaro Hattori, in a 2021 Bunshun column, recalled that he had 56 by February 2014 and that opponents had been walking him far more often since the previous autumn.

The 2014 Senbatsu was his first national tournament. Before it, he said he wanted to hit one off the Koshien backscreen, an unusually large claim from a player who, Tanigami writes, normally gave modest team-first answers. In the first round against Mie, with two outs and nobody on in the first inning and a full count, he hit a fastball over center that bounced off that screen. He hit a second that day. Okamoto later explained to Tanigami that coach Masaaki Kosaka had told him to say something big for once. He also said he had once told a reporter he hoped to steal a base at Koshien, as a joke.

The next game was the other half of the tournament. Against Sano Nichidai and left-hander Daiki Tajima, Okamoto struck out twice and then took the mound in the bottom of the 10th, where Chiben Gakuen lost on a walk-off, web Sportiva reported in 2018. Tajima said afterward that he had found Okamoto frightening. A Pacific League scout told Sportiva in 2014 that first-round talk was possible, while another criticized him for chasing a low ball with a man on third.

Yomiuri named him alone in the first round that October, and Japanese papers called him a future cleanup hitter. Tanigami noted how hard it had been to develop high school sluggers at Yomiuri. It took time: BASEBALL KING counted one career home run before 2018, then .309 with 33 home runs and 100 RBIs that year.