After a tragic loss, Yousuke Yamamoto's existence spirals into dull routine until a chance encounter with the fearless Eri Yukisaki, facing a chainsaw-wielding giant. Enthralled by Eri's bravery, Yousuke joins her quest to confront this mysterious foe. Through Eri's enhanced abilities and Yousuke's newfound purpose, they form an unlikely partnership to protect others. As their alliance deepens, they edge towards vanquishing their enemy, yet Eri harbors a hidden truth that could alter everything.