A waitress at Tae's restaurant, Sanjō Tsubame becomes Yahiko's sweetheart. She was saved by him from the ronin her family worked for as Yahiko stopped them from robbing the Akabeko. She is very shy and soft spoken. When Kenshin enters a living hell after the supposed death of Kamiya Kaoru at the hands of Yukishiro Enishi, Tsubame pleads for Kenshin to help Yahiko fight back against one of Enishi's abandoned allies and brings Kenshin back into the world of the living. Later she and Yahiko have a child.

In Seisōhen/Reflection, Tsubame and Yahiko had become a couple and Watsuki has mentioned in his notes Tsubame and Yahiko's son 'Shinya'; they become a couple in the manga storyline.