Sensei Wu

Master Wu is a wise old man and the mentor to the Ninja. He is the First Spinjitzu Master's second born son, Misako's brother-in-law, Garmadon's younger brother, and Lloyd's paternal uncle. Wu endured a traumatic childhood as his big brother Garmadon was bitten by The Great Devourer and infected with evil. After a battle between brothers broke out, Wu cast him into the Underworld.

Not long after, Wu began to train four teenagers - Cole, Jay, Kai, and Zane - in the ways of Spinjitzu before sending them out to find the Golden Weapons. After Lloyd released the Serpentine, Wu discovered his nephew's destiny was to become the Green Ninja, and immediately oversaw the four Ninja as they trained Lloyd. Wu was was later reunited with Garmadon's wife, Misako, who joined Wu and the Ninja in their battle against The Overlord and the Stone Army. When Lloyd defeated the Overlord, Garmadon was purified of evil, much fo Wu's relief. When the Nindroid conflict began, Wu was captured by the Digital Overlord and corrupted into a spiteful cyborg. After the Digital Overlord was vanquished, Wu was purified and aided the Ninja as they fought the Overlord and his army. The battle ended when Zane sacrificed himself to defeat the Golden Master.

The loss of Zane disbanded the Ninja team until they reunited to find him on a mysterious island. Upon discovering their whereabouts, Wu sent out Nya before uniting with the Elemental Masters. At the Corridor of Elders, Wu helped fight an old enemy and his army until his brother was banished to the Cursed Realm in an effort to end the war. Following the loss, Wu retired and opened a tea shop. When his first pupil, Morro, possessed Lloyd and embarked on a quest to find his father's tomb, Wu trained Nya to harness her element and fight the ghosts. After Morro claimed the Realm Crystaland freed his master into Stiix, Wu helped evacuate the city as Nya destroyed the Cursed Realm, along with Morro, who accepted his fate. Shortly after, a vengeful djinn sought vengeance for the destruction of his home realm, and he trapped Wu in the Sword of Souls. After Jay made his final wish, recent events were reversed and Ninjago was left safe.

On the Day of the Departed, Wu led the Ninja during their day of remembrance, as he commemorated his father at the old monastery. However, Cole accidentally revived the Ninjas' old enemies, including Morro, who confronted Wu at the monastery and told him of Yang's plans to isolate Cole and defeat the Ninja. With Morro's help, Wu reunited the team before setting off to Yang's Temple, where he witnessed Cole becoming a human once more.