I.O.I Sub Unit Profile and Facts I.O.I (아이오아이) Sub Unit the first sub-unit of I.O.I. consisting of 7 Members. Nayoung, Chungha, Kyulkyung, Sohye, Yoojung, Doyeon and Somi. I.O.I Sub Unit officially debuted on August 9, 2016. I.O.I Sub Unit Fandom Name: – I.O.I Sub Unit Official Colors: – I.O.I Sub Unit Official Sites: – I.O.I Sub Unit Members Profile: Nayoung (Rank … Continue reading I.O.I Sub Unit Profile