Seiji Uebayashi (上林 誠知)
- Bats Left, Throws Right
- Height 6' 1", Weight 176 lb.
Seiji Uebayashi has been an All-Star outfielder in Nippon Pro Baseball.
Uebayashi was a bench player for Japan in the 2013 U-18 Baseball World Cup, going 3 for 9 with 2 walks, 2 steals, a double, triple, 3 RBI and 4 runs for the Silver Medalists.  He was picked by the Softbank Hawks in the 4th round of the 2013 NPB draft; he was a third baseman in the minors in 2014.  Moving to the outfield in 2015 (with Nobuhiro Matsuda blocking the path at third), he made it to the big club for a cup of coffee. In his first at-bat in NPB, he singled off Dae-eun Rhee of the Chiba Lotte Marines. He hit a grand slam off Rhee in the 6th to become the youngest player in Hawks history to go deep, breaking Hiroyuki Yoshida's record. He hit .318/.333/.591 in 45 plate appearances for the season and also won a minor league MVP. 
Seiji played in the Asia Winter League following the 2015 season.  He was only 4 for 19 with a double and 7 whiffs for the Hawks in 2016. He won a starting spot in 2017 and hit .260/.302/.434 with 13 homers. He excelled on defense, with 168 putouts, 10 assists and no errors to lead Pacific League outfielders in assists and fielding percentage. He made the PL team for the 2017 NPB All-Star Games. In Game 1, he started in left and hit 6th. He struck out against Raul Valdes and fanned against Akitake Okada before Alfredo Despaigne pinch-hit for him.  In Game 2, he replaced Yuki Yanagita in the lineup and manned right while Shogo Akiyama moved from RF to CF to replace Yanagita there. He did not get to bat; when his turn came up, Hideto Asamura batted for him.  In the 2017 Japan Series, he got only one at-bat in six games as Softbank downed the Yokohama BayStars; Alfredo Despaigne, Yuki Yanagita, Akira Nakamura and Yuya Hasegawa saw the bulk of the outfield action. 
In 2018, he improved his hitting to .270/.315/.488 with 88 runs, 26 doubles, 14 triples, 22 homers, 62 RBI and 13 steals in 17 tries while leading PL flyhawks in assists (10) and double plays (4).  He was the first PL player to hit 14 triples in a season since Larry Raines way back in 1953.  He was on the PL leader list in runs (7th, between Haruki Nishikawa and Shogo Nakamura), hits (149, tied for 8th with Kensuke Kondo), triples (obviously 1st; 5 ahead of Sosuke Genda), total bases (269, 6th, between Masataka Yoshida and Matsuda) and times plunked (7, tied for 8th). He hit three triples in the final stage of the playoffs and drove in 10 runs against the Seibu Lions, becoming the first NPB player to hit three triples in a single post-season and joining Terrmel Sledge as the only players with 10 RBI in one stage of the playoffs.  In the 2018 Japan Series, his two-run homer off the Hiroshima Carp's Yusuke Nomura was the big hit in game 4 as the Hawks went on to take another Series. He hit .130/.167/.261 for the Series, a let-down after his big playoff performance.  In the 2018 Nichi-Bei Series, he led Japan with a .476 average, .024 behind event leader Yadier Molina, as the NPB stars beat the MLB stars. In Game 4, his 9th-inning single off Kirby Yates scored Kazuki Tanaka to make it 3-2. He then scored the tying run on a hit by Kosuke Tanaka. He also scored the winner in the 8th inning the next day, when Takuya Kai singled off Dan Otero to bring him in.  He played for Samurai Japan in their friendly exhibition against the Mexican national team in early 2019. 
After his big 2018 in his age 22 season, more was likely expected in 2019 but instead, he struggled. He hit only .194/.254/.360 in 99 games for Softbank and wound up back in the minors briefly. He sat out the 2019 Japan Series as Softbank went to Yurisbel Gracial, Yanagita, Despaigne and Nakamura instead on their way to a three-peat.