Celty Sturluson, a courier with a peculiar assignment, must transport a suspicious red handbag coveted by various groups across Ikebukuro. Pursued by enigmatic foreign-speaking pursuers, she unwittingly entangles the city's denizens in the bag's enigma. Meanwhile, renowned actor Yuuhei Hanejima, alias Kasuka Heiwajima, descends on Ikebukuro for a televised venture to scout a couple for his film, only to face a perilous threat from an anonymous online antagonist. As Shizuo's despised adversary plots against the superstar, revelations about their intertwined pasts come to light, leaving Shizuo to reckon with his intense animosity towards the culprit.