As an elementary school student in Gifu Prefecture, Ōno played for local team Arasaki Baseball boys where he was a catcher, pitcher and third baseman.

Following graduation from high school, Ōno enrolled at Toyo University where he was on the bench in his first spring behind junior year catcher, Daisuke Tanaka.

[1] In the Tohto University Baseball League, Ōno played in 55 games racking up 43 hits, a batting average of .259 with 6 homeruns and 19 RBIs.

On April 11, he made his starting debut against the Fukuoka SoftBank Hawks and helped lead Shugo Fujii to keeping runs off the board.

Even though Fujii had moved to the Yomiuri Giants in the off-season, Ōno became the main catcher for southpaws and that year, 14-winner Masaru Takeda allowing him to make even more appearances.

On October 15, due to back pain, he experienced his first ever de-registration from the first team but made his comeback in the first game of the Pacific League Climax Series.

Compared to previous seasons, Ōno's performance with the bat dropped considerably but he led the league in runners thrown out percentage with .323.

Ten days later on July 14, Ōno would return to the top team but would only catch for Wolfe and Keisuke Tanimoto leading to his poorest yearly statistics up until that point.

He would hit over .250 with an OPS of over .700 to mark his best batting totals to date while on the defensive side he was the only catcher in NPB to have throw runners out with over a 40% success rate at .421.

On May 17 in a game against the Chiba Lotte Marines with the scores tied at 1–1 in the 11th inning, Ōno hit his career first walk-off home run off Takahiro Matsunaga.

[12] At this point, hometown team, Chunichi Dragons entered the race for his services after making public their desire to improve their catching stocks and on December 9, the move was finalised.

[13] On December 9, 2017, the Dragons revealed they had captured Ōno's signature having agreed to a 3-year, ¥250 million deal and receiving the 27 jersey previously worn by Motonobu Tanishige.

[18] Fighters pitching coach Kazuyuki Atsuzawa described Ōno's ability to lead in comparison to Shinya Tsuruoka as similar to motherly figure, Kakaadenka.