In a utopian world where happiness is absolute, a suicide crisis threatens the very existence of humanity. As countless lives are lost and the global happiness index continues to decline, the AI Government assigns Mimosa the mission of restoring happiness and bringing population growth back to the world. By chance, Mimosa encounters Ash, a man laughing at an advertisement featuring her face. Upon discovering that his happiness level is far below that of everyone else, she sets out to cure him. But as she delves deeper into Ash’s condition, Mimosa uncovers a key that could change the fate of their world forever.