According to Deadline, Rila Fukushima (The Wolverine) has been cast as Tatsu Yamashiro aka Katana in the third season of Arrow. She replaces Devon Aoki (Sin City) who was announced in July, but has apparently departed The CW series due to scheduling conflicts.
The role is described as a major recurring role since Yamashiro is:
“One of Oliver’s mentors in the flashbacks and a critical influence on his journey to eventually become The Arrow of present day.”
Perhaps, the role is or has become bigger, than Aoki originally thought? Maybe we’ll be seeing Katana is the present day as well?
Arrow Season 3 will debut on October 8th.