Shohei Ohtani publicly declared his intention to challenge Major League Baseball while he was still at Hanamaki Higashi High School. At the time, however, what he envisioned was not becoming a two-way player. In his mind, he was going to America as a pitcher.

Despite being highly regarded as a hitter, his heart was set on the mound. Why such a strong commitment to pitching?

Because, as he put it, “As a pitcher, I had too many unfinished things from high school.”

Ohtani appeared at Koshien twice—once in the summer of his second year and again in the spring of his third year. Both times, his team was eliminated in the first round. During the summer tournament against Teikyo, he came out of the bullpen while dealing with a leg injury and could not pitch anywhere near his true ability. In his third year, he faced Osaka Toin and even hit a home run off Shintaro Fujinami as a batter, yet once again, injuries prevented him from delivering the kind of pitching performance he had envisioned.

When Ohtani looks back on Koshien, he recalls mostly defeat and frustration. Especially as a pitcher, he felt there was so much left undone.

That lingering sense of incompletion became fuel.

He did not simply want to become a professional player.
He wanted to finish what he had started.

It was the Hokkaido Nippon-Ham Fighters who later told him, “Why not do both?”—planting the seed of what would become his two-way career. But at the core of it all was something much simpler:

A desire to fully see through the version of himself that he felt had never been completed.

Source

This quote comes from a Japanese book published in Japan and is not currently available in English.

Baseball Chronicle I: Japan Years 2013–2018, p.67