Da-eun, Seo-jin, and Jae-won all went to the same elementary. Three friends who were all going to different middle schools get together for their friend with the nickname ‘Chirpy.’ Chirpy was also their close friend in elementary school but left the world from an accident. The children try to commemorate Chirpy in their own way. Not Too Heavy, Not Too Light is a story of children trying to escape the trauma of a friend’s death. In the process, the complex emotions of the children are revealed, and the director collects each detail one by one and weaves it together. The film approaches the audience’s heart calmly and softly.