The Ikebukuro Calamity is the fourth chapter in the Saika Arc manga adaptation.
Synopsis[]
It picks up where Shizuo asks Celty if she suspects him of being the slasher, but Celty quickly reassures him that she doesn't think he would act that way, especially since it was another Dollars member that was attacked. She then mentions she is not looking for the slasher just for the Dollar's sake but for her own sake too, as she was stabbed by them too. Shizuo is shocked to hear this and becomes fully interested in finding the slasher to kill them for injuring his friend.
After Celty calms Shizuo down, she visits Izaya Orihara and asks him for information regarding the slasher. Once paid, Izaya provides the information she needs, telling her about a demon blade known as Saika.
Elsewhere in that chat room the spammer "Saika" logs on and spams the chat with messages about slashing people until they are able to meet Shizuo Heiwajima.
Quotes[]
Shizuo: "And if I don't take care of it, it's pretty likely that I'll end up destroying myself."