On October 2, 2016, Blockberry Creative announced through Naver that they would be forming their first girl group through an 18-month long project. Between October 2016 and January 2017, four members (HeeJin, HyunJin, HaSeul, and YeoJin) joined the group; each member released a single album usually having a solo track and another track performed with other members, under the group's Korean name "Idarui Sonyeo" (). In March 2017, the group's first sub-unit, Loona 1/3, was introduced, made up of previous members HeeJin, HyunJin, HaSeul and a new member, ViVi. Loona 1/3 released the extended play "Love & Live" with a single of the same name on March 13, 2017, with a television promotion on SBS's "Inkigayo", On April 27, they released a repackaged version of the extended play, titled "Love & Evil", with the single "Sonatine". "Love & Live" and its reissued version reached number 10 and 24 respectively on South Korea's Gaon Album Chart.