You can see a photo of Tama in the drama here.
The name of his character is Kuraki Youichirou.
For now, that's all the information I have. I don't know what role his character will actually play.
Edit: The following information comes from TV Life.
Tamamori's character will die. He gets sent to Yamapi's character's (Masato) undertaker place as an identity unknown body, but Masato recognizes him as someone who had an interview for a part-time job at the izakaya that Masato worked at. From Eikura Nana's character, Masato finds out that Tama was stalking this girl called Reina (I have no idea who plays her, apparently it's not mentioned and it's not on the official website either) and when some delinquents or something like that goes to bother Reina and all, Tama's character gets involved and stabbed while protecting her. After knowing all that, Masato then decides to find out more about the truth of Tama's character's death.