She is beautiful, human, and a villain. When she was a child living in an apartment building, the Great Devourer attacked Ninjago City. Her parents tried to escape with her, but there was no room left in the elevator. To save Harumi, they put her in the elevator alone. Harumi survived alone and grew up to become the Emperor's adopted daughter to seek revenge on the Ninjas who failed to save her parents. She approached the Ninjas, pretending to like Lloyd while planning to betray them. She secretly burned down the Imperial Palace and infiltrated the Ninjas' headquarters. Later, her identity was revealed, and she resurrected Lloyd's father, Garmadon. During a riot caused by Garmadon, the building Harumi was in collapsed, and no one came to save her. However, the villain Overlord resurrected her.

He is handsome, a Ninja, and the leader. He addresses Kai, Jay, Cole, and Zane as older brothers (Hyeong) and Nya, Skylor, and P.I.X.A.L. as older sisters (Nuna). He is the Green Ninja and the son of Garmadon and Misako. Being half-human and half-Oni, he has a human appearance with green eyes. He is half-hating and half-still-loving Harumi.

He is handsome, the Ninja of Fire, and highly competitive. He is Nya's older brother. He hates Harumi. He is in a 'some' relationship with Skylor.

He is handsome, the Ninja of Lightning, and in charge of comedy. He hates Harumi. He is Nya's boyfriend.

He is handsome, the Ninja of Earth, and hates Harumi. He has a responsible, serious, and reliable personality. He loves cake and can sometimes be playful or quirky when he's in high spirits.

He is handsome, a Nindroid, and the Ninja of Ice. Although a robot, he speaks human language. He hates Harumi. He is in a 'some' relationship with P.I.X.A.L. He has a very serious, logical, and altruistic personality.

She is beautiful, the Ninja of Water, and hates Harumi. She is Jay's girlfriend. Like her brother Kai, she hates losing.

She is beautiful, the Ninja of Amber (Absorption), and hates Harumi. She is in a 'some' relationship with Kai. While she appears independent and tough on the outside, she has a warm and loyal personality on the inside.

She is beautiful, a Nindroid, and although a robot, she speaks human language. She is in a 'some' relationship with Zane. She hates Harumi and has a warm, devoted personality.