The Pittsburgh Pirates are again without an Asian player, 
trading relief pitcher Ryota Igarashi to Toronto for future considerations.  The site 
Jays Journal says he
won’t be considered for a position in the Jays’ bullpen given that it’s already full, so he’s purely a depth pickup and that will spend the season with Triple-A Las Vegas. As a pitcher with a decent splitter that can generate ground balls but also rack up strikeouts, though, he’s a solid, low cost pickup for Vegas’ bullpen.
Igarashi, a 32-year-old out of Chiba who has 5 wins in 79 Major League appearances, signed a minor-league contract with Pittsburgh in December, a move that completely escaped my notice. 
Pittsburgh has experimented with a few Asian-born players, but none have lasted an entire season, as I noted 
in a December post about some rumored free agent targets.  My favorite, for sentimental reasons because he was a guy I wanted to see succeed after finally getting to the US, was Masume Kuwata, the 39-year-old pitcher signed in 2007.  The sequence on his Baseball Reference wiki, though, shows a typical Pirates acquisition:
"1987-1994: The Glory Years," "1995-1996: Injury," "1997-2002: Post-Injury," "2003-2006: Further decline," "To the USA."