The Hiroshima Carp drafted Maru out of Chiba Keizai University High School in the third round of the 2007 NPB draft and he would spend almost three full seasons in the minor leagues before making his NPB debut towards the end of the 2010 season. Since the start of the 2011 season, Maru has been a fixture in Hiroshima’s outfield, and although he moved around between all three outfield positions earlier in his career, he is now almost exclusively a center fielder.
Maru’s first two seasons as a full-time player were unremarkable as he hit only .244 with 13 home runs, 23 stolen bases, and a 90/164 BB/K ratio in 237 games. However, he turned a corner in 2013, and in almost a full season for the Carp (he appeared in 140 of 144 games), he posted a .273/.376/.425 slash line with 14 home runs, 29 steals, and a much improved BB/K ratio of 85/103. 2014 was the arguably the best year of his career to this point, as he improved his slash line to .310/.419/.491 with 19 HR and 26 SB while playing in all 144 games. 2015 saw some regression in his batting average down to .249, but the power remained consistent (19 HR), as did his durability (143 games). So far in 2016, Maru is back to hitting for a higher average (.292), and he is currently on pace for his first 20/20 season with 10 HR and 11 SB through 71 games.
It’s easy to look at Maru and compare him to another former Central Leaguer who made the jump to MLB, Norichika Aoki (OF, Mariners). Maru hasn’t piled up hits at the same rate that Aoki did during his NPB career (Aoki had four full NPB seasons with an average of at least .344), but they have similar styles of play, and both have put up similar power numbers in Japan (Aoki’s NPB career high in HR is 20). Maru, however, is a superior defender and likely stays in center field should he ever make the jump the big leagues. Maru has come a long way since his draft year and while he is not elite in any one area, he does a lot of things well and is one of the more hard-nosed players in the league. He could almost certainly play everyday in the big leagues for someone right now, so look for him to be a regular for the Japanese WBC team.
Aoki was 30 when he made his MLB debut after 7 full seasons in the NPB; Maru in currently in his sixth full season and he won’t turn 28 until the start of his seventh. Hiroshima has never received a great deal of financial support, and they are rarely able to keep their star players, so they could be inclined to post Maru before he is eligible for domestic free agency in a couple years, similar to what they did with Kenta Maeda (RHP, Dodgers) after his sixth season with the club.