KAI sees the world ending in an explosion of corpse-eating trees as an irresistible opportunity to lighten the burden of guilt she suffers when her pseudo sibling dies. She sets out with her classmates on a journey to stop the world double-ending as her home city attempts to destroy the deity-like trees, resulting in the contamination of nearby water sources and an unlivable wasteland. On her journey, KAI ping-pongs between extremes: debilitating inhibition and adrenaline fueled power trips.

Perennial is an apocalyptic psychological comic, exploring themes of power vs. helplessness, acceptance vs. control, and ambiguity vs. clarity.