Berryz Kobo was a Japanese idol girl group formed by Up-Front Promotion in 2004 and associated with Hello! Project. The group's members consisted of Hello! Project Kids members Saki Shimizu, Momoko Tsugunaga, Miyabi Natsuyaki, Chinami Tokunaga, Maasa Sudo, Yurina Kumai, and Risako Sugaya; Maiha Ishimura left the group in 2005.

Momoko Tsugunaga is a former Japanese singer, actress, and radio personality. Tsugunaga joined Hello! Project as a member of Hello! Project Kids at the age of 10 and later became part of the girl groups Berryz Kobo and Buono! Following Berryz Kobo's hiatus, she became the playing manager of Country Girls. In 2017, Tsugunaga retired from entertainment to become a kindergarten teacher.