Orix Buffaloes On August 8, Kosuke Kawachi pitcher held contract negotiations at the team's facility in Maishima, Osaka, and signed for an annual salary of 5.5 million yen, down 500,000 yen (estimated amount). I was a bit confused at first because it was the first time in my life that I couldn't pitch due to an injury, but I really was able to focus on building my body during the past year. I weighed 80 kilograms, and my muscle mass was also increasing. I wanted to make it a year that I could say, 'I'm glad I had this year,' so I'm glad in that respect," he recalled.

He joined the team as the second pick in the 2023 draft out of St. Catherine High School, and is a right-handed pitcher who underwent medial collateral ligament reconstruction surgery (commonly known as Tommy John surgery) on his right elbow in August 2024, his first year. This season, he started anew as a development pitcher, and his rehabilitation process went smoothly. In October, when he returned to full-scale action in the Phoenix League, he felt confident, saying, "I'm not in pain, and I feel like I'm back to normal. The quality of the ball itself has improved compared to my first year."

He inherited number 63 jersey that Yamazaki wore when he joined the team, and is expected to be a future ace candidate. "Next season will be my third year, so I'm at an age where I'm really expected to produce results. I'll work hard in the offseason so I can get off to a good start in training camp, and next year I'll be able to return to the team as a regular player and contribute to it," he said enthusiastically.