Akinobu Okada tendered his resignation with the Hanshin Tigers on the 14th. Okada has said that he decided to take responsibility for the Tigers finishing in second by resigning his post as manager of the Tigers. The owner of the Tigers, Shinya Sakai, reportedly offered Okada a 3-year extension by Okada was not interested and declined.
Earlier on the 17th, rumors placed baseball commentator Akinobu Mayumi (55) at the helm to replace Okada, but it now appears as though those reports were a bit premature -- the front office has not officially committed to hiring Mayumi yet.
(If I recall correctly, a sports program I watch earlier today mentioned something about a potential announcement early next week.)