Araragi Koyomi, now in his university years, delves into a blend of oddities and mysteries during the 'Monster Season.' Prompted by his underclassman from Naoetsu Highschool, Higasa Hoshiame, who brings unsettling rumors of an elementary school girl's disappearance, Araragi teams up with Hachikuji Mayoi, Oshino Shinobu, and Ononoki Yotsugi to unravel the enigma. As they step into this contemporary world of peculiar happenings, the youth's pursuit of truth illuminates the evening shadows with a brilliant glow.