"Even if the path isn't always straight, we go forward with confidence, because we trust where we're headed."
— Kai




Kai the Red Ninja of Fire




Red Ninja



  • Sword of Fire
  • Fire Elemental Blade
  • Fire Techno Blade
  • Kai's Jadeblade
  • Obsidian Sword
  • Fire Aeroblade





Deepstone Outfit





Hair Color

Brown, Spiky Hair

Professional Status
  • Ninja
  • Elemental Masters


Personal Status



Way of the Ninja

Voice Actor

Vincent Tong

Kai is one of the major protagonists in LEGO Ninjago: Masters of Spinjitzu. He is the Red Ninja of Fire, and Nya is his younger sister. He and his teammates were chosen to protect the Green Ninja. He also plays the role of the main character in the pilot season of LEGO Ninjago: Masters of Spinjitzu, and continues to play a similar role throughout the series. His father was a friend of Sensei Wu and his parents are the previous Elemental Masters of Fire and Water. 

He and his teammates were chosen to protect the Green Ninja. He was the last Ninja to join the team, last to get his Golden Weapon, and the last to unlock his True Potential.


Kai has brown, spiky hair. He is often seen with a focused expression on his battle-scarred face, a slight notch visible on his left eyebrow.


Kai is very hotheaded, prone to taking action before he thinks things through which matches with his element. He is capable of making careful observations when the need arises, but his emotions often override his caution. His single-mindedness made interaction with his teammates difficult at first (especially due to his worry about Nya), but he eventually learned to work with the other Ninja. He can be arrogant at times, insisting that he is better than his peers and growing depressed when he seems to be lagging behind their training.

Kai has something of a stubborn side, believing that he is in the right until overwhelming evidence to the contrary is presented. This is especially pronounced during Lord Garmadon's stay on the Destiny's Bounty; Kai repeatedly accused the four-armed villain of treachery or plotting despite Garmadon's insistence that saving Lloyd was his primary concern at the time. Kai's stubborn streak lends him incredible determination that allows him to bolster the team's spirit in the face of impossible odds.

The most prevalent facet of Kai's personality is his dedication to people he cares about - if someone can earn his friendship, he will stop at nothing to protect them. Much of his stubbornness and recklessness are due to his desire to help his loved ones, either directly or by becoming strong enough to defeat anyone who might threaten them with their plans. In turn, his friends and family work to balance out Kai's more extreme traits, causing him to become a levelheaded mentor.


Kai favors swords in combat, taking up a curved silver blade against the Skulkin when they attacked his shop. He used the Sword of Fire as his primary weapon until it was lost, and then switched to wielding regular katanas. He eventually gained an Elemental Blade that allowed him to harness his fire abilities to an even greater degree. A few years after Lloyd defeated the Overlord, Kai, along with the other three ninja (Cole, Jay, and Zane), received the Techno Blades, a weapon which allows the ninja to hack into any electronics.
Ninjago kai



Way of the Ninja

He was the fourth to become a ninja. He use to be a blacksmith with his sister, Nya. He did a lot of training to unlock spinjitzu. Soon he found the three ninjas called Jay, Zane, and Cole.

The Golden Weapon

Kai lime eyes ep 5

Kai with lime eyes

Kai became the ninja of the element of fire.

Can of Worms

Kai got spit by Spitta and he can see the snakes are elves and gingerbreads.

The Snake King

Kai ZX

Kai ZX

Kai got a new suit (ZX). He found out that Nya was the Samurai.

The Green Ninja

He was the only one who didn't unlock his True Potential. He was so obsessed so he defeats Garmadon to unlock it. When he saves Lloyd and unlocked his True Potential, he discovered that Lloyd is the Green Ninja.

All of Nothing

He retrieved the Sword of Fire from Pythor.


Kai's True Potential (NRG Kai)

Island of Darkness

Kai's suit was transformed (Kimono) in the Temple of Light.

Enter The Digiverse

Imagined his head is an airhead.



Kai Kimono (very left)

Kai Evolution

Kai's Evolution

  • The name, Kai, means "strong," "victorious," and "recovery," in three Asian cultures, all of which fit his hotshot attitude and the Ninja's battles. His name may also be derived from the Japanese word Akai, meaning "red."
  • Kai is the last Ninja to join the team, the last to claim his Golden Weapon, the last to unlock his True Potential, and the last to have a love interest. On the other hand, he was the first Ninja introduced in the series and the first to tame his respective dragon.
  • He appears to have a fear of Christmas-related themes, as shown in "Can of Worms," when the Venomari's venom causes him to see things like gingerbread men and elves.
  • Since "The Invitation," Kai's had feelings for Skylor, which she initially used against him until she began to return them.
  • Kai and Nya's parents were the First Elemental Master of Fire and the First Elemental Master of Water.
    • He inherited the elemental powers of his father, while Nya inherited her mother's.
  • Kai is mentioned to be aquaphobic during "Stiix and Stones".


Click here to view the gallery.



Wu · Garmadon · Cole · Zane · Jay · Kai · Lloyd
Allies: Misako · Nya · Dr. Julien · Falcon · P.I.X.A.L. · Ronin


Leader: Lord Garmadon (Formerly)
Samukai (Deceased) · Wyplash · Kruncha · Frakjaw · Chopov · Nuckal · Krazi · Bonezai


Anacondrai Tribe: Arcturus · Pythor P. Chumsworth
Fangpyre Tribe: Fangtom · Fangdam · Fang-Suei · Snappa
Venomari Tribe: Acidicus · Lizaru · Spitta · Lasha · Zoltar
Constrictai Tribe: Skalidor · Bytar · Chokun · Snike
Hypnobrai Tribe: Skales · Slithraa · Mezmo · Rattla
Other: The Great Devourer (Deceased)

Stone Army

Creator: The Overlord
General Kozu · Giant Stone Warrior · Stone Warrior · Stone Swordsman · Stone Scout


Creator: Cyrus Borg
General Cryptor · Nindroid Drone · Nindroid Warrior · Min-Droid

Anacondrai Cultists

Chen · Clouse · Zugu · Eyezor · Kapau · Chope · Krait · Sleven

Elemental Masters

Ash · Bolobo · Elemental Master of Light · Paleman · Karlof · Tox · Shade · Neuro · Elemental Master of Gravity · Gravis · Griffin Turner · Skylor · Elemental Master of Water · Elemental Master of Fire

Ghost Warriors

Leader: The Preeminent
Morro · Chain Master Wrayth · Blade Master Bansha · Scythe Master Ghoul Tar · Bow Master Soul Archer
Ghost Ninja: Attila · Hackler · Howla · Ming · Spyder · Wooo
Ghost Warriors: Cowler · Cyrus · Ghurka · Pitch · Pyrrhus · Wail · Yokai


Grundle · Spykor · Starteeth · The Leviathan · Treehorn · Craglings · Mud Monsters · Ice Serpent · Walliper
Dragons: Fire Dragon (Flame) · Lightning Dragon (Wisp) · Earth Dragon (Rocky) · Ice Dragon (Shard) · Ultra Dragon
Elemental Dragons: Golden Dragon · Elemental Earth Dragon · Elemental Fire Dragon · Elemental Form Dragon · Elemental Gravity Dragon · Elemental Lightning Dragon · Elemental Metal Dragon · Elemental Mind Dragon · Elemental Nature Dragon · Elemental Poison Dragon · Elemental Shadow Dragon · Elemental Smoke Dragon · Elemental Speed Dragon · Titanium Dragon


Bizarro Ninja · Brad Tudabone · Carridi · Cathy · Dareth · Ed · Edna · First Spinjitzu Master · First Mate · Fred Finley · Gayle Gossip · Gene · Genn · Hibiki · Lou · Mystake · Night Watchman · Noonan · O'Doyle · Patty Keys · No-Eyed Pete · Rufus Macallister · Captain Soto · Phantom Ninja · Warden Noble · Rachel Sparrow · Suzie Wheeler · Yang