Seine is a Wolf Fang (Elf in the anime and later TRPG Replays) Swashbuckler-Border Patrol from the Log Horizon TRPG replay novels and is role-played by Ayasato Keiji.

She makes an appearance in the Log Horizon 2 anime along with the other members of Nyanko-tei, and participates in Operation Capture as a member of the Akiba Raid Party.