Isaki, whose full name is listed as Chelsey Yssacky Miranda Bautista, is a Filipina performer from Gapan, Nueva Ecija. Before becoming part of OONA, she was known as a second-generation member of MNL48, giving her early experience in idol performance, training, and public promotions.
Beyond singing and dancing, Isaki is also described as musically inclined, with profile sources listing bass, organ, and piano among the instruments she can play. She also has a background in dance competitions, can perform hip-hop, previously practiced arnis, and has expressed interest in cyber security. Her official OONA position still needs confirmation, so it is best to avoid labeling her as main vocal, dancer, rapper, or leader unless confirmed later.