In addition to the Hanshin Tigers, the Softbank Hawks and Yokohama Bay Stars could be interested in Ryota Igarashi. The Rakuten Eagles were also interested, but may have dropped out.
Now that the Tigers have done all they can with Tsuyoshi Nishioka (as in, the ball is now in his court), the Tigers may soon begin serious negotiations with Igarashi.
Source: Sanspo 11/10/2012
Known offers to Tsuyoshi Nishioka, according to Sports Hochi Osaka:
Lotte - two-years, 400M yen
Orix - two-years, 500M yen
Hanshin - two-years, 600M yen
He has also spoken to one or more other teams.
Source: Sports Hochi Osaka 11/10/2012
The Orix Buffaloes are prepared to make time for Nishioka if he wants to meet again. Source: Sports Hochi Osaka 11/10/2012