Tsuna returns home and is surprised to see a wedding invitation addressed to him. He is even more surprised when he finds out that it's from Reborn and Bianchi. He thinks that it is a joke but is proven wrong when Kyoko and Haru arrive to pick him up. The three arrive at the church's Bride Waiting Room and see Bianchi wearing her wedding gown, to Haru's and Kyoko's delight.
Tsuna decides to check on Reborn and sees him wearing his wedding clothes. He congratulates Reborn by patting him on the shoulder and is surprised to see it detach from his body. Tsuna then hears a voice and Dino arrives and explains that Reborn is replaced with a doll since he ran away. He explains to Tsuna that he had met Reborn earlier that day and congratulated him, only to discover that the wedding is just a misunderstanding between Bianchi and Reborn who had woken up from a nap to see her in a really good mood. Tsuna is worried that Bianchi would find out that Reborn ran away, and Dino agrees and predicts that she would go berserk and kill everyone. He adds that she would act the same if they try to stop the wedding and explains that Reborn saw that coming too and left a replacement. Dino then reveals that the doll Reborn can talk and move with the help of a remote control.
After the wedding finishes, the guests sit down for a meal and nobody seems to notice that Reborn has been replaced by a doll. Tsuna then asks Gokudera if he is okay since Bianchi is there but Gokudera reveals that he is wearing a pair of sunglasses that causes him to not see anything. At the bride and groom's table, Bianchi gives the doll Reborn something to drink which causes it to malfunction for a while. Bianchi gets suspicious, pulls out some guns and asks the room for Reborn's whereabouts. However, Tsuna and Dino are able to calm her down by saying that Reborn is just nervous.
Bianchi and Doll Reborn then go to change their clothes. Tsuna and Dino go to change the doll and are surprised to see Gokudera arrive and inform them that he knew it was a fake since he is able to hear some motor sounds. Tsuna begins to panic but Gokudera wants to help them and understands what happened before they explained. He snatches the control away from Dino when Lambo arrives and demands to play with the controller, making Tsuna nervous.
Back at the wedding hall, the cake is unveiled and Tsuna and Dino are surprised to hear that Bianchi is the one who made it. Suddenly, Doll Reborn steps on the pattern of Bianchi's face due to Lambo snatching the control. This causes Bianchi to get suspicious again. However, Dino is able to save everyone by snatching the control and making the doll tell Bianchi that it is testing her. The light is turned off then, and Bianchi and Reborn begin to circle the room and light the candles on the tables. Annoyed with Lambo, Gokudera tries to confront him but since he is unable to see, ends up confronting Bianchi instead which causes him to collapse and destroy the control. The doll begins to malfunction and sprays Bianchi with some oil, angering her and awakening a new ability that is able to make anything she touches her poison cooking. However, she calms down when the real Reborn arrives and gives her a wedding ring that is really a weapon which shoots out some piano wire...
Note: Bold + Italicized = First Appearance