日本Lea is a young girl on the brink of death. She begins her final challenge, a thesis that seeks proof in the belief that happiness can be multiplied, as can the feelings of sadness, loneliness, and misery. Unfolding the research, she discovers the "Werther Effect", a phenomenon that creates a negative domino effect. She turns to her work on a project which will achieve the opposite effect, something which would be named the "happiness effect". Utilizing an eclectic, individualistic approach to experimentation and the power of positive thinking, connections and equations lead her on a path to uncover ultimate happiness.