Ikumatsu 幾松 is the owner of a ramen shop called 北斗心軒 hokuto shinken. She and her husband, Daigo 大吾 intended to turn the ramen shop into the best in Edo, but her husband died due to Jouishishi's terrorist activities before they could do it, as a result of which she holds a deep grudge against Jouishishi 攘夷志士 members. Katsura Kotarou 桂 小太郎 worked at her ramen shop when he was injured and on the run from Shinsengumi 真選組. He helped to rescue her when her brother-in-law betrayed her and tried to sell her into brothel 
Although she now knows that he is a Jouishishi member, they are on friendly terms. Katsura's subsequent television interview by Hanano Saki 花野 咲 was carried out at her ramen shop.
Gintoki is known to be a frequent customer, and he would patronize her shop every time he gets some money from his jobs. She also has a quite friendly relationship with Gintoki. When we see her talking to Gintoki in her restaurant, and she says "It's been a long time!"; her demeanor is friendly and they chat comfortably.
- Ikumatsu's name is the same as the name of the geisha that hid Kogoro Katsura (the real person whom Katsura Kotarou was based on) during 1860s; she later became his wife.
- Sorachi Hideaki, Gintama, VIZ media, Vol. 7, Lesson 55, page(s) 127.
- Gintama Official Character Book Gin-chan neru! ISBN 4-08-874086-6, pg. 133.