MONOWAVE follows Mono, a newborn Guardian spirit destined to protect the four Emotions: Anger, Anxiety, Happiness, and Sorrow. The Emotions were guided and nurtured by the Prism Tree at the heart of the world. When the Emotion Shards within the Prism suddenly vanish, the Emotions scatter across the land and the Prism Tree begins to wither. Mono sets out to reunite the Emotions and restore harmony to the land.