Katana is married to Oliver’s handler in Hong Kong, and will appear in flashbacks to Oliver’s time with ARGUS. Knowing her has been a critical influence on the Arrow of present day. It’s unclear if Katana will be seen in present-day Starling City.
Katana is a member of the all-female crime-fighting group, Birds of Prey. One member of the group, Black Canary, has already appeared on Arrow. She was recruited by Amanda Waller to join the United States’ Justice League of America. Both Arrow and Katana are affiliated with The Outsiders, an organization formed of seven weapon-based clans: the Sword, the Arrow, the Spear, the Fist, the Shield, the Ax, and an unknown weapon.