In the aftermath of the tragic 'Great Hinamizawa Disaster' caused by toxic gas two decades prior, the desolate village of Hinamizawa remains a haunting memory shunned by society. Yet, on a fateful night, five strangers stumble upon this forsaken place nestled amidst the mountains. In the alternate realm of Yoigoshi-hen, stemming from Tsumihoroboshi-hen, Mion Sonozaki, a former villager, seeks refuge at the deteriorating Furude Shrine during a relentless downpour. Alongside her is Akira Otobe, a man in search of his missing companions. As they take shelter, they encounter other mysterious individuals within the shrine's walls. However, when a sudden murder disrupts their uneasy peace, suspicions arise, pointing fingers at Mion herself—an enigma, considering her alleged demise during the calamitous events of the past.