Tsuna is taken by Reborn, Bianchi and Lambo to eat some expensive sushi. When Tsuna asks if it is okay to eat something that expensive, Reborn, Bianchi and Lambo run for it leaving Tsuna to pay for the meal. As Tsuna tries to bargain with the owner, Takeshi arrives and Tsuna finds out that he's the son of the owner. The owner tells Tsuna that he will treat him for the food since he is a friend of Takeshi but tells him that he should pay for what the newly arrived Reborn, Bianchi and Lambo are eating, much to his dismay. As the three leave again, Lambo trips and Tsuna tries to get some money from him but he only had a stone. The owner examines what the three ate and informs Tsuna of his debt: ¥70,000. As Tsuna tries to think of what to do, Reborn arrives again in a costume and suggests that Tsuna should work there to which the owner agrees. Takeshi offers to help Tsuna which he accepts.
As the two wash some dishes, Hayato arrives and offers to help too. Hayato took Tsuna's job but ends up breaking some dishes causing Tsuna's debt to rise by ¥30,000. When Tsuna and Takeshi are about to finish the dishes, Reborn and Lambo return and eat some of the tuna with Hayato which causes Tsuna's debt to rise again by ¥100,000, much to his dismay. Bianchi then arrives and offers to take responsibility for Hayato's actions. Bianchi takes the remaining tuna and makes some of her food which is delicious. The owner tells Tsuna that he would forget his debt if Bianchi makes more of her dish which she agrees. When Bianchi finishes her dish, Tsuna, Takeshi and his father collapse and Reborn realizes that Bianchi accidentally developed a new technique which delays the reaction to the poison. In the end, Tsuna is forced to work to clear his debt...
*Note: Bold + Italicized = First Appearance