''Orange Town Arc'' episode 7

In episode 7, after knocking out the mayor for being in the way Luffy provoked Buggy by yelling his most hated sentence ''BIG NOSE''. As he lost his temper Buggy launched the Buggy bomb at them, but Luffy bounced it back with his rubber balloon ,and so Buggy came to realization that Luffy is too an ability user. The battle began and the first to challenge Luffy on behalf of Buggy was the acrobat Cabaji ,and since he's a sword user Zoro took him on instead.
While facing Cabaji's numerous and ticky acrobat techniques, Zoro seemed in a pinch as he kept getting hit on his old wound again and again. But as soon as he got up again showing no sign of waver or weakness, Cabaji apprehends that Zoro's sword technique is a one that manifests his strong will into the blade, thus defeating him would not be an easy task.
In the mean time, Nami took the opportunity of them being too occupied in battled, and went to the treasure room to get hold of what she wants, Buggy`s treasure and the Grand Line map. Regrettably, the guard woke up but he was dead drunk and there`s no way Nami would miss that oppening ,so she pretended that her chest suddenly started hurting to drop him off guard and knock him out . WOW! she truly does live up to the name ''conniving thief ''.
Returning to the battle, Zoro oppenly declares that he's finally getting tired of keeping up with Cabaji's useless acrobatic specials, and ended the battle with one strike of one of his strongest three-sword style techniques: ''Demon Slash'' ,and then he fell on the ground while saying: '' Luffy, I'm going to sleep''.
The second half of episode 7, is the start of the battle of ability users between Buggy and Luffy. Buggy announces that seeing Luffy's straw hat pisses him off, for it keeps remainding him of  ''that despicable redheaded basterd''. As rubber can't bounce blades back, Luffy is at a bit of a disadvantage in this fight for his oppenent's strongpoint is one of his weakpoints. In the process of clashing between the two sides of this abnormal fight, Buggy slashed Luffy's hat and that got him so immensely worked up for hurting Shanks' oath hat. And it turned out that Shanks and Buggy were at the same ship once as pirate apprentice, they were comrades. As soon as he steps on the staw hat Luffy brusts into rage landing on Buggy a painful blow on the balls, while telling him to never say that they were comrades again. And thus Buggy decided to tell Luffy about the story of his grudge against Shanks.