Volume 15

Volume 15 is titled "Straight Ahead!!!".

Cover
The outside colored cover is red with yellow borders. The title logo is dark yellow (fading from light), turquoise, and gold, and the author's name is written in turquoise.

An excited Usopp stands in the center with Luffy underneath him flying facefirst towards the reader. Behind Usopp are Dorry and Brogy holding up their respective sword and axe, and light blue portraits of Dorry and Brogy are shown behind their respective character.

Chapters

 * 127. Den Den Mushi (電伝虫): Dorry wakes up due to Brogy's weapon being blunt. Sanji impersonates Mr. 3 when Crocodile calls him, but Crocodile gets suspicious and sends Mr. 2 after them.
 * 128. Pride (Pirate Flag) (海賊簱): The Straw Hat Pirates head for Alabasta, and so does Smoker after intercepting their call.
 * 129. Straight Ahead!!! (まっすぐ!!!): Dorry and Brogy assist the Straw Hats in battling a giant goldfish and the two groups bid each other farewell. Later, Nami suddenly collapses from fever.
 * 130. Maximum Speed (最高速度): Nami attempts to shake off her fever and navigate to Alabasta, but Vivi decides that Nami needs a doctor first. They enter a winter area, when Zoro spots something weird.
 * 131. Tin Plate Wapol (ブリキのワポル): The Straw Hats battle the Wapol Pirates, whose captain, Wapol, can eat anything. However, Luffy manages to send Wapol flying away.
 * 132. See? (ね): The Straw Hats reach a winter island, but are attacked by angry villagers. However, the Straw Hats are welcomed after they bow in submission to the citizens.
 * 133. Adventure in the Country Without a Name (名もなき国の冒険): Dalton guides the Straw Hats around the island, revealing that the only doctor lived on top of a mountain and was inaccessible. However, Luffy and Sanji decide to climb the mountain with Nami on their back.
 * 134. Dr. Kureha (Dr.くれは): Dalton reveals that Wapol was once their king, but he ran away when a pirate named Blackbeard attacked. Unbeknownst to him, Wapol and his crew are nearing Drum Island. As Sanji and Luffy battle lapahns, Dr. Kureha comes down to a village to treat patients.
 * 135. Lapahn (ラパーン): Sanji continues fighting the Lapahns to no avail, while Dalton learns that Wapol has returned. Wapol intends to both take his kingdom back and get revenge on the Straw Hat Pirates.
 * 136. The Man Called Dalton (ドルトンという男): Dalton battles Wapol, but intercepts Chess' and Kuromarimo's arrows to protect the citizens. The Lapahns cause an avalanche on the mountain.

SBS Notes

 * Oda explains the "sailing ceremony" the Straw Hats did in Chapter 100.
 * The birthdays for Luffy, Zoro, Nami, Usopp, and Sanji are revealed.