The Rakuten Eagles announced today that Senichi Hoshino will remain in their organization as a senior adviser.
Source: official announcement
[UPDATE 11/10 @ 4:02am]
Hoshino may have signed a five-year deal worth a total 500 million yen. It apparently took him this long to sign because he wanted to wait for former coaches he worked with this season to find new jobs first (like Yoshinori Sato).
Source: Sponichi 11/9/2014