Wawa!! is the second chapter of the Dollars/Mika Harima Arc.
Mikado Ryuugamine is excited with his new life in Ikebukuro as well as his chance encounter with the 'Black Rider'. Situated within his dilapidated apartment, he researches the urban legend on his computer with clear excitement.
Elsewhere at Seiji Yagiri's house a girl named Mika Harima is knocking on the door. Leaning against the door, Seiji attempts to keep it closed with his body weight, internally noting that his 'stalker' has already figured out his home address. Seiji threatens to call the cops which appears to stop Mika, but only a few minutes later Mika breaks into the room through the open window. Having clearly seen 'something', the girl becomes very visibly nervous while promising that she won't say anything. Not willing to take any chances, Seiji bashes her in the head with a bat.
Seiji's elder sister, Namie Yagiri , bursts into the apartment while yelling out to him. After she makes sure he is okay, she orders the men she had brought along with her to take care of the body and reassures her brother that the police won't get him.
In the chatroom, TarouTanaka is still talking about when he saw the infamous Black Rider. The user Kanra responds by seemingly going into more intricate detail about the Black Rider from rumors they had heard about it from acquaintances and around the city.
Elsewhere in a parking garage, a group of men in jumpsuits are standing around waiting for someone. One of the men is noted to be MIA; only to appear moments later in a bloodied and bruised condition. Taken aback by this, the men look around and notice the Black Rider sitting atop the parking garage incline, confused by their presence. One of the bespectacled men walks up to it, demanding the Black Rider backs off. The dark motorcyclist, however, smashes their front wheel against the bespectacled man's face, prompting the other men to take action. In response, the Black Rider materializes shadows which seem to take the shape of a scythe and quickly takes down the men one at a time.
After the Black Rider knocks out most of the men, they open the trunk of the van to find two people bound and gagged inside. One of the remaining men makes a direct attack at the Black Rider while they are distracted and manages to knock off the rider's helmet, only to discover that the Black Rider is headless.
Namie: "No one can have you. You're my Seiji."