|Romanized Name:||Sai Kobayashi|
|English Name:||Sai Kobayashi|
|Occupations:||Heatwave Pirates (current), Swordsman (current)|
|Epithet:||Death Blade (死ブレード, moarte Lamă) (?)|
20 (after timeskip)
- "A sword isn't just a blade with a hilt. It's an extension of oneself that exemplifies the hard years of work that one must attain to master its power."
- —Sai explaining to Lokai what the meaning of a sword is.
Sai was born in the East Blue to a family of nobles. However, he was very weak when he was born, resulting in him being a stillborn until he was two years old. When he awoke a few months after his second birthday, his sister, Kumada, was born. Because of him being so weak during his early years, Sai's parents gave all their attention to Kumada and shunned Sai whenever they could. This all changed when Sai was five, where he met two boys who didn't outcast him: Raiken and Miyazaki Montizuma. The three became best friends, even declaring how they were going to become pirates one day. They took part in mock pirate activities around the town, such as "sticking up" stores and fighting with wooden swrods. Sai even started training in combat and swordsmanship under Zaku, Raiken and Miyazaki's dad.
When Sai's dad found out about this, he forbade Sai from seeing the two again, citing that they had, "the blood of a devil" withink them. Sai, in outrage, ran away from home and went to live with the Montizumas. Kumada found out about this and broke into the Montizumas' house to drag him back home, but the brothers stopped her.
To seperate himself from the family that never loved him, Sai stood atop the tallest building in the city and burned his family's ornate seal. When he was 19, he set off with Raiken and Miyazaki as the Heatwave Pirates.
Rebellion in Noroka City
When the Heatwave Pirates landed in Noroka City, they found out about the plan to ovethrow Moku, the city's tyrannical leader. They sought help from Jingfei, the city's former governor, who planned to rebellion. Sai befriended Kylie O'Halloran, a budding young swordswoman whom Sai offered to train, and ended up falling for. However, she betrayed Sai and the rebellion by killing many of Jingfei's soldiers during the initial attack, revealing herself to be one of Moku's subordinates.
Overcome with betrayal, Sai battled Kylie and manages to defeat her, but spared her life and told her she had a chnace to live a good life instead of the one she led.
Conspiracy in the North Blue
The crew was welcomed by the Nagarais when they landed on an island located in the North Blue. They learned from the Nagarais that a secret underground special forces unit known as Strikeforce was afoot, and the couple gave them the names of a couple of people to eliminate to save the town. They agreed, but Sai knew that something was up.
When eavesdropping, he discovered that the Nagarais were Strikeforce's true leaders, and that the people they eliminated were a threat to the revelation of the unit. Sai battled Canto, one of the Strikeforce's most feared leaders, and manged to defeat him.
Next, the Heatwave Pirates landed on Solaris and met Riku, a cook at the Corona Restaraunt. She declined the offer to join their crew, but promised to serve them at the eatery as long as they were in town. They heard rumors of a Marine attack on the island for harboring fugatives of the World Government and decided to help. Sai and the others discovered that Akihiko Iwao, Riku's superior, was really a Colonel of the Revolutionaries sent ot help the island.
Sai was the first to reassure that Akihiko's death would be avenged (because Akihiko was the closest thing Riku had to a father). Sai had to go up against Rear Admiral Titan, who was sent as back up in the attack. Sai managed to destroy the Rear Admiral's ship, using it as an advantage to defeat the Marine. When Riku decdied to join the crew after Johanson's defeat (after listening to Akihiko's dying words: "Follow the path of your dreams"), Sai greeted her pleasantly, due to them sharing a similar past.