Past: He lost his parents to a UFO in his childhood. He almost died himself due to an order from the future, but was saved by a costumed warrior fighting with a mysterious watch. Since his family was kidnapped, he became hostile toward aliens. He transforms into Mist Shadow to fight when aliens appear. He is your older brother. Personality: Cool-headed and serious. Affiliation: Y Academy Student Council President / Middle School 2nd Year, Class A

Past: Long ago, he was kidnapped by aliens along with his friends and subjected to experiments merging them with other animals. While his friends were completely modified, Baek Sa developed snake skin on his back. Through many twists and turns, he stole a Viper Connector from the spaceship and escaped. He became close with Ma Sam-sik and formed the Y Academy Mafia, turning into a delinquent. Later, he joined Mu Eun-yul and Ji Myo-han's group when they requested cooperation against the aliens. Abilities: His weapons are the Sky Snaker and an electric guitar. Playing the guitar transmits ultrasonic-like attacks to opponents.

Affiliation: Y Academy Middle School 2nd Year Personality: He may seem cold or expressionless, but he actually has a warm heart and takes great care of others. Traits: From a wealthy family. Abilities: Yo-kai HERO The Viper and cloning techniques.

Affiliation: Y Academy / Middle School 1st Year, Class A Personality: Has a strong sense of justice. He is a positive person who doesn't sweat the small stuff and quickly forgets bad experiences. Abilities: 1. Kengo Benimaru - Transforms with the red cat Yo-kai, Bakera. 2. Wild Boy - Transforms with the yellow cat Yo-kai, Goromi. 3. Blue Moon - Transforms with the blue cat Yo-kai, Burupon.

Affiliation: 1st Year, Class A He has a cute puppy-like face, is short, and has blue hair. He is Ji Myo-han's friend and originally comes from a rural village. He is the eldest son of a famous family of comic storytellers but is terrible at it. His guardian spirit is Alma, and he transforms into Little Commander.

Affiliation: 1st Year, Class A He calls himself a man of coincidence. He loves heroes and dislikes dangerous things. He is in the same class as Myo-han and somehow ended up joining the YSP Club.

A popular guy. He is handsome and plays tennis. He has long hair and is the same age as Tae Woo-ri, Mu Eun-yul, Baek Sa, and Ma Sam-sik. He often bickers with Tae Woo-ri. He is a member of the YSP Club. His guardian spirit is Miho, and he transforms into Nine-Tail.

Affiliation: Y Academy / Middle School 2nd Year Past: He was a member of the mafia led by Baek Sa and Ma Sam-sik. Personality: Full of passion and sometimes aggressive. Abilities: Possessed by his guardian spirit Black Lion, he transforms into Lion King.

She has a crush on Mu Eun-yul.