It's 9 o'clock and a Namimori Middle School student is getting beaten up by two students from the next town. The next day, Reborn informs Nana Sawada and Tsuna about the acts of violence, with the victims being found seriously injured and with missing teeth. Nana begins to worry about Tsuna's safety and suggest that he should go to some self-defense classes. Tsuna tries to complain but Reborn sides with Nana.
Meanwhile, Ryohei is on his daily morning jog, thinking about the attacked students. He then comes across a stranger who is one of the students that injured the other students. Ryohei thinks that he is there to transfer schools and join his boxing club and the stranger agrees to join if Ryohei can beat him.
As Tsuna and Reborn are walking to school, Tsuna is looking at all the flyers that his mother gave him about self-defense classes. As the two continues walking, Tsuna notices that some of the school prefects are patrolling the streets and thinks that the attacks are gang related. Just then, Hibari arrives who tells him that Ryohei has been attacked.
Tsuna and Reborn immediately head to the hospital and see Ryohei with six broken bones, seven cracked, and five missing teeth. Ryohei tells Tsuna that the attacker is a middle school student from Kokuyo town and to be careful. Ryohei also tells Tsuna to not tell Kyoko about what really happened. Just then, Kyoko arrives and her eyes begin to water at the sight of her brother, thinking that Ryohei was injured while climbing the chimney in their bathhouse. Tsuna and Reborn exit the room to give the two some privacy and see that the hospital is full of Namimori students. One of the students informs Tsuna that the targets are not only prefects, but any Namimori student. Tsuna begins to panic when Tetsuya Kusakabe and another prefect pass by, talking about Hibari going after the criminals.
Elsewhere, Hibari manages to arrive at Kokuyo Land and defeat all of the gang members, coming face to face with the gang leader. Meanwhile, Leon's tail falls off, Reborn ominously telling Tsuna that it was an unlucky sign...
Note: Bold + Italicized = First Appearance