In 2011, Dir.F and Kenmochi first met at Design Festa Tokyo. As a label manager at Tsubasa Records, Dir.F wanted to launch a new music project with provisional female members, while Kenmochi wanted to produce new music differing from his instrumental music under Nujabes's Hydeout Productions label after the 3.11 Disaster in Japan. The two decided to form a group and named the project ‘’Suiyōbi no Campanella’’. In 2012, Dir.F met KOM_I at their videographer friend’s house party and invited her to join the group. KOM_I had no prior music experience until she joined the group and joined while in high school. Originally, Kenmochi and Dir.F sought a trio of girls for the group, but the idea quickly was abandoned. For their initial debut, another female singer appears on the cover and sings but there are no credits within the liner notes. Eventually, KOM_I became the only vocalist. She was chosen as a vocalist originally because Kenmochi liked the mismatch between her voice and the rap music he was producing.