Lotte’s Koki Yamaguchi Explodes with 38 Home Runs… The Batting Form He Learned from Teruaki Sato’s Video and the Secret Behind His Breakout Season
“I can only make my living with a bat.”
“My dream is to hit 30 home runs.”
Koki Yamaguchi (26) of the Chiba Lotte Marines, who has been saying this since he turned pro, has finally had his “breakout season.” The power hitter, who had faced setbacks despite being touted as the “future cleanup hitter,” has made significant strides after refining his batting form and transforming his mental approach.
This season, he hit 38 home runs, ranking second in the league. Although he made a dramatic leap forward, he himself said,
“I never imagined I’d be able to hit this well,”
revealing his honest feelings.
He had been steadily improving, hitting double-digit home runs in both ’22 and ’23, but hit a wall when he managed only two in ’24 and seven last year—results that fell short of expectations.
Then, this season, after much trial and error, he finally found the “answer.”
“I started the year on the first team, but since I wasn’t producing results, I was sent down to the farm team in April. The manager told me, ‘You’re not making solid contact on fastballs,’ and while I was thinking about what to do, I found a good clue.”
That hint was a batting video of the Hanshin Tigers’ star slugger, Teruaki Sato (27). Although Sato bats left-handed, Yamaguchi analyzed his swing as if he were a right-handed batter—just like himself—and began putting it into practice the very next day. By adopting a simple stance with the bat resting on his shoulder, he mastered a batting form that allows him to handle fast fastballs.
This season, he’s not only hitting home runs but also maintaining a steady batting average of .277. Yamaguchi’s approach at the plate is extremely simple.
“Even when I wasn’t in top form, there were quite a few at-bats this year where I hung in there and managed to get a hit. But I don’t really think about things like ‘I’m going to go for a home run’ or ‘I’m going to get a hit’; I just focus on ‘hitting the ball hard.’
I only consciously aimed for a home run once this season—during the final game against the Nippon Ham Fighters (October 1), when I came up to bat in the ninth inning with two outs and the bases loaded. But the result was a groundout to third (laughs). I guess you really shouldn’t aim for it.”
From the November 6, 2026 issue of *FRIDAY*
Koki Yamaguchi made a dramatic leap from 7 home runs last season to 38 this season. In Part 2, we delve into the mental shift that fueled his breakthrough, his feelings toward his family, his first selection to Samurai Japan, and the new goals he has set for next season.
[YouTube] FRIDAY TV presents: “[Exclusive Interview!] Chiba Lotte’s Koki Yamaguchi: ‘This Is How You Hit Home Runs at ZOZO Marine!!’”In this video, the “Makuhari Cannon”—who blasted 38 home runs this season—opens up about the “secret” to his home run production at ZOZO Marine Stadium, where strong sea breezes blow, his thoughts on “Samurai Japan,” and the cheers from the fans.What is the true face of this “Japanese slugger” that Lotte fans have been eagerly awaiting?
PHOTO： Takehiko Kohiyama