|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 Kobayashi is the Swordsman and First Mate of the Heatwave Pirates. He is the best friend of the Montizuma Brothers. He gained the scar on his eye when he was 12 from a camping trip after a miscalculation of adding gasoline to the fire.
Sai wore a gray tunic undershirt under dark red and orage shoulder gear with spiked tips along with a brown and gold belt on his tunic. He also bears a ponytail on the top of his head.
Sai now has longer hair that constantly droops over in front of his face. He wears a dark red and regular red rob-like tunic with a gold trim, along with a gold sash around his waist. He wears red pants tucked into black and gold-lined boots.
Sai now puts his hair up tied together with a top-knot. He has black armor with a golden trim just above his chest and wears red robes that extend to his calves with a golden sash around his waist. He wears black wrist guards with a gold trim. He also has a black and red cape over his shoulders.