▁and ▁M ina ▁were ▁introduced ▁as ▁J elly fish ▁Entertainment ' s ▁first ▁female ▁tra ine es ▁on ▁the ▁M net ▁surv ival ▁show , ▁Produ ce ▁ 1 0 1 , ▁where ▁ 1 0 1 ▁female ▁tra ine es ▁from ▁various ▁companies ▁competed ▁to ▁debut ▁in ▁an ▁eleven - member ▁girl ▁group ▁that ▁would ▁promote ▁for ▁a ▁year ▁under ▁Y MC ▁Entertainment . ▁After ▁placing ▁ 2 nd ▁and ▁ 9 th ▁respectively ▁in ▁the ▁final ▁episode , ▁Se je ong ▁and ▁M ina ▁deb uted ▁as ▁members ▁of ▁I . O . I ▁in ▁May ▁ 2 0 1 6 . ▁▁ 2 0 1 6 : ▁Deb ut ▁with ▁Act . ▁ 1 ▁The ▁Little ▁Mer ma id ▁ ▁Despite ▁den ying ▁earlier ▁reports ▁of ▁Se je ong ▁and ▁M ina ▁debut ing ▁in ▁a ▁ 3 - member ▁girl ▁group ▁in ▁June , ▁J elly fish ▁Entertainment ▁confirmed ▁on ▁June ▁ 7 ▁that ▁the ▁two ▁I . O . I ▁members ▁would ▁debut ▁within ▁the ▁month ▁in ▁what ▁would ▁be ▁the ▁company ' s ▁first ▁girl ▁group . ▁Because ▁of ▁Y MC ▁Entertainment ' s ▁special ▁terms ▁in ▁which ▁I . O . I ' s ▁members ▁are ▁allowed ▁to ▁do ▁activities ▁under ▁their ▁respective ▁companies ▁while ▁I . O . I ▁was ▁on ▁break ▁or ▁while ▁the ▁group ▁promoted ▁in ▁sub - un its , ▁there ▁were ▁no ▁comp lications ▁with ▁the ▁plan . ▁ ▁N ay ou ng ▁was ▁also ▁confirmed ▁as ▁a ▁member ▁on ▁June