Chio-Chio Yoritomo was a colonist on Pern.
Chio-Chio was a friend of Ita Fusaiyuki; the two had been room-mates on board the Buenos Aires and neighbours on Irish Square in Landing before Ita moved with Kenjo Fusaiyuki to their home at Honshu Stake.
Kenjo apparently asked Chio-Chio to marry him first, but she refused.
When Kenjo was murdered by Avril Bitra, Chio-Chio went with Emily Boll and Pierre de Courci to Honshu Stake to break the news to Ita, who told them in response that she would continue managing the stake alone. When they returned to Landing, Chio-Chio told the others that Ita was «very traditional», and not showing grief so as not to belittle the deceased Kenjo. Chio-Chio later left in tears at the thought of Kenjo being killed after cheating death so many times.
The youngest daughter of Ita and Kenjo, Chio Fusaiyuki, was probably named after Chio-Chio.