In a desperate bid to save his ailing childhood friend, Akari Hizamaru embarks on an extraordinary journey that involves entering an underground ring to face a ferocious bear. Struggling against insurmountable odds, Akari soon realizes he possesses peculiar powers that may turn the tide in this life-and-death brawl. However, a heart-wrenching betrayal leaves him shattered, questioning the fate of his friend. Through unexpected encounters, Akari finds himself entangled in a mission to Mars led by an organization determined to eradicate mutant cockroaches threatening humanity. As the pieces of this intricate puzzle slowly connect, the truth behind Akari's abilities and the sinister link between the monstrous insects and the deadly virus gripping mankind begin to unravel.