Youko Itoigawa (糸魚川 養子 Itoigawa Yōko) is a librarian at the Kamiyama High School. Before marriage her surname was Kooriyama (郡山).
In the 1960s she was the President of the Classics Club when she was a second-year student at Kamiyama High School. Now she works as librarian at the same school.
- Her husband is briefly shown in a semi-flashback on her age.
- Her daughter is also briefly shown during the aforementioned flashback.
|Koten-bu series and Hyouka Featured Characters|
|Main characters||Eru Chitanda • Houtarou Oreki • Satoshi Fukube • Mayaka Ibara|
|Students||Ayako Kouchi • Fuyumi Irisu • Jirou Tanabe • Junya Nakajou • Kaho Juumonji • Koreyuki Tani • Kurako Eba • Masashi Toogaito • Mayu Hongou • Misaki Sawakiguchi • Muneyoshi Kugayama • Shouko Yuasa • Tomohiro Haba • Yasukuni Yoshino|
|Other||Jun Sekitani • Haruna Anjou • Kayo Zenna • Masakiyo Ogi • Omichi • Rie Zenna • Tomoe Oreki • Youko Itoigawa|