Thirty-year-old Ryoma Nogami earned his domestic free agent option last year. He may be thinking about exercising the option this winter. The Hanshin Tigers are interested and might consider pursuing him if he becomes available.
The Tigers are looking for additional arms for their starting rotation, particularly after they lost Randy Messenger to an injury and struggled to fill his spot. It did not help that Shintaro Fujinami needed to spend a bulk of time at Ni-gun making adjustments to his mechanics this year. Takumi Akiyama and Atsushi Nomi were the only two pitchers that managed to keep their spots in the rotation the entire season.
Nogami does like playing for the Seibu Lions and could end up staying with them, but is also said to be interested in listening to offers from other teams.
Source: Nikkan Sports 10/22/2017
[UPDATE 11/4 @ 1:59pm]
Nogami has not yet made a decision about his option. He did tell reporters on November 3 that Hisanobu Watanabe (Lions senior director) asked him to stay. He also told reporters that he wants to take his time with his decision, is asking people around him for their thoughts, was told by his wife that the decision was his to make.
[UPDATE 11/5 @ 12:04pm]
The Bay Stars may also be interested in Nogami. They are looking to upgrade their starting rotation with another right-handed pitcher.