Wait, UPD might refer to "Ultra Pure Division," a sub-unit formed by some of the idols from another group. For example, the UPD is a sub-unit of the idol group "UP Front" (UPF). The UPD includes idols like Honoka Kuromiya and Mayu Tomotaka. But the user mentioned Anna Oonishi, so maybe she was part of an earlier or different UPF group?