The media learned on October 9 that thirty-four-year-old Ryota Arai is planning to retire after the season. A press conference is scheduled for tomorrow (October 11).
Arai began his professional career in 2006 with the Chunichi Dragons. He never played in more than forty-five games in a season while playing for the Dragons. He later had a chance to play alongside his older brother, Takahiro, when he was traded to the Hanshin Tigers for Keisuke Mizuta on December 24, 2010.
The Arai brothers became the first brothers in NPB history to record walk-off hits for the same team in the same year in 2011 (Ryota on April 19, 2010 and Takahiro on April 22, 2010). They also became the third brother combo to hit home runs in the same game on July 29, 2012.
Source: Nikkan Sports 10/10/2017
[UPDATE 10/11 @ 2:51pm]
Arai went 0-for-2 (G6, F7) in the last regular season game of his career on October 10. Teammates tossed him into the air five times after the game.
Source: Daily Sports 10/11/2017
[UPDATE 10/12 @ 12:14am]
Arai held a press conference on October 11 and announced his decision to retire. He told the media he decided to retire because he started the year thinking that this would be his last chance to make it. He thought about a lot of things and ultimately felt this was the right time to retire.
The first person he sought advice from was his brother Takahiro. He talked to him in July. His brother’s advice: it is your life, you make the call.
Source: Hanshin 10/11/2017