Yuri

Yuri is the former member of Citron and an old friend of Kanon.

She was only seen briefly in Kanon's flashback, in which Kanon still had long hair. Yuri was a very happy girl with the dream to perform at Naru Hall. She has a considerably perfect voice and always sings with joy. But for some unknown circumstances, the group had split up and Kanon deviated from the group and started to perform solo. Two years later, after Kanon had become a successful solo idol, she and Lime sent Kanon flowers to give her courage to perform at the Narusawa Seaside Hall.

(Source: Wikia)