One Piece School Volume 5

Big Brother is a Worrier is the fifth volume of One Piece School, including chapters 19 - 23.

Cover and Volume Illustration
The cover has a light blue-green background. The logo is red-orange, and the author's name is dark red.

The cover display Luffy walking forward, with Ace and Sabo following behind him.

Chapter 19
School Has Started (学校は始まった) Luffy allows Sanji and Zoro to continue fighting, only stopping Buggy's interference. When they have finished, the three of them along with Nami and Usopp vow to be friends. Back in the present day, Koby notices that most people act the same as at their entrance ceremony, though he remarks that Buggy has gotten nicer.

Chapter 20
Big Brother is a Worrier (お兄ちゃんは心配性) Luffy forgets his gym uniform, so his brothers, Sabo and Ace, go bring it to him. They run into various students on the way, and Sabo helps to save somebody from a collapsing building.

Chapter 21
Rumored Wicked Girl (噂の悪女) Koby hears rumors about Robin dating Mr. Kuzan Aokiji, and decides to investigate. He quickly discovers that she's seemingly also dating Trafalgar Law, Eustass Kid, Rob Lucci, and Crocodile, not knowing how to react. Chopper avoids answering when he's asked about it, and Robin is suddenly confronted by Spandam, with Koby watching. However, she suddenly reveals that they had actually been planning a surprise birthday party for Koby and Luffy, and she had been inviting the different students.

Chapter 22
Café Baltigo (カフェ バルティゴ) Koby and Zoro run into Sabo while investigating a group called "RA", and he invites them into Café Baltigo. After sitting with Perona, she informs them about Donquixote Doflamingo and warn them to be careful. This prompts the duo to train, and after Zoro leaves, Koby is attacked by various members of Doflamingo's group. However, he is saved by RA, the Revolutionary Army, promising to keep Sabo's involvement secret from Luffy.

Chapter 23
White-Bearded Old Man (白いひげのおっさん) Luffy and Zoro meet Whitebeard in an inn, becoming friendly with each other. Whitebeard then returns to Moby Dick School, where he's attacked by Crocodile, who states that the students of New World Middle School are preparing to fight back against Whitebeard's rule as Emperor. Crocodile states that he will become the next Emperor, and Whitebeard challenges him and the rest of the students to try their best to defeat him.