Like the First Grand Gravity, two DIMENSIONs (units) will be formed. As each DIMENSION exists as an individual team, each DIMENSION will have its own schedule. The two DIMENSIONs are officially named EVOLution and LOVElution. Each unit will consist of eight members. The first seven members of each DIMENSION will be voted in by fans across the world using the Cosmo App, while the last member will be chosen between S15 and S16, with their DIMENSION already decided. Unlike the First Grand Gravity, all 14 S's participating will be voted on at the same time. For seven days, from April 21 to April 27, WAVs will choose one S for each DIMENSION. Once a pair of two S's with the most selections to go to which DIMENSION is decided, that pair of S's will be eliminated from the vote the next day. After seven days, the Gravity will take a break from April 27 to 28, and then continue for two days, from April 28 to 30.[1] On April 22, it was announced that YuBin has been placed in LOVElution,[2] followed by SeoYeon on April 23,[3]Kaede on April 24,[4]DaHyun on April 25,[5]SoHyun on April 26,[6]HyeRin on April 27,[7] and Nien on April 28.[8] On May 1, LOVElution was voted to debut first while EVOLution will debut second.[9] On July 2, Xinyu was revealed to be S15.[10]
On July 28, it was announced that they would make their debut on August 17 with the mini album LOVElution <ↀ>.[11] During the LOVElution showcase, SeoYeon stated that unlike Acid Angel from Asia and +(KR)ystal Eyes, LOVElution will not disband if they do not reach 100,000 sales.[12]