He made his debut with the ichi-gun Baystars late in the 2011 season and was the team's starting center fielder on Opening Day of 2012. That would end up being probably his best season, as he played in 141 games, hit .268, stole 24 bases and lead the Central League in triples with 7. He also won a Golden Glove that season. He missed some time with a broken nose and/or cheekbone the next season but still got in 126 games, hitting .258 and winning a second Golden Glove award.
His playing time with the top team dropped off considerably after the 2013 season and I'm not entirely sure why. I think some of it was due to injury - he broke a finger in training camp in 2014 - but some of it appears to be that he became less effective and the Baystars had better options. He only got into 63 games in 2014, 70 in 2015, 36 in 2016, 47 in 2017 and 11 in 2018. Following the 2018 season the Baystars released him. He was hoping to get a contract with another NPB team but none was forthcoming. He ended up signing with the Monterrey Sultans of the Mexican League, joining former NPB players Yadir Drake, Yamaico Navarro and Wirfin Obispo. He hit .293 for the Sultans but he was released at the end of June.
Aranami is one of those rare Japanese players who have a pre-rookie card. As an insert to the 2008 USA Baseball National Teams Box Set, Upper Deck created a set of memorabilia (and autographed) cards for the 2007 Japanese Collegiate National Team. Aranami's first cards are in this set. His first BBM cards are from the 2011 Rookie Edition (#091) and 1st Version (#319) sets. He had his first Bandai and Konami in 2012 as well as a "Star" insert card from Calbee but his first regular Calbee card wasn't until their 2013 set (#032). Here's a bunch of his cards:
|2008 Upper Deck USA Baseball National Teams Box Set #JN-1|
|2011 BBM Rookie Edition #091|
|2011 BBM 1st Version #319|
|2012 BBM 2nd Version #655|
|2013 BBM 1st Version #388|
|2013 Front Runner Baystars Rookies & Young Stars #06|
|2014 BBM Speed & Smart #14|
|2016 Calbee #139|
|2017 BBM Baystars #DB59|
|2018 Baystars Team Issued Set #4|