She is first seen during the Earthquake traveling with Naoko to Tokyo. Jirō Horikoshi rails her injured leg with his Slide Rule. Then he carries her on his back to a temple. He leaves Kinu and Naoko behind to get help from Naoko's neighbor.
Jirō study at the Royal University of Tokyo for years. Kinu send him a package, where inside lie his slide rule, his shirt and a letter. Instantly, Jirō stands up and runs outside looking for her, be she cannot be found anymore.
Naoko meets Jirō in Karuizawa. She talks about Kinu, that she get her second child.
Kinu (絹) means silk.