Wait, IVE's song "Ive" is a self-titled intro song, and one of the members, Wonyoung, dances with a phone, and there's a concept of a girl who's yearning for love. But I don't think the term "Year Girl" is used in their actual music. Maybe it's a nickname given by fans. Alternatively, maybe it's a different group. Let me think about other girl groups and their concepts.
Another angle: Maybe "Year Girl" refers to a member's nickname. For example, if a member is known as "Year Girl" due to her themes. But that seems unlikely. Alternatively, if a member has a song or a solo performance under that title. But I can't recall any. 15 Year Girl Hot Sex Video
Alternatively, maybe it's a reference to a song title from a girl group where "Year Girl" is part of the concept. Let me check. For example, maybe in a group like IVE, Aespa, or NewJeans. For example, IVE's song "Ive" has the concept of "I've loved you" which could be misheard as "Year Girl". Alternatively, maybe they have a music video that's referred to with a concept like that. Let me check. Wait, IVE's song "Ive" is a self-titled intro