Past: Lost his parents and younger sister to a UFO as a child. He almost died due to an order from the future but was saved by a costumed figure fighting with a mysterious watch. Since his family was abducted, he became hostile toward aliens. He transforms into Mist Shadow to fight when aliens appear. Personality: Cool-headed and serious. Affiliation: Y Academy Student Council President / Middle School 2nd Year, Class A

Past: Long ago, he was abducted by aliens along with his friends and subjected to experiments merging them with other animals. His friends were completely remodeled, while Baek Sa grew snake skin on his back. After many twists and turns, he stole a Viper Connector from the spaceship and escaped. He became close with Ma Samsik and turned wayward, forming the Y Academy Mafia. Later, he joined Mu Eunyul and Ji Myohan's group when they requested cooperation against the aliens. Abilities: Uses the Sky Snaker and an electric guitar as weapons. Playing the guitar transmits ultrasonic-like attacks.

Affiliation: Y Academy Middle School 2nd Year Personality: He may seem cold or expressionless, but he actually has a warm heart and takes very good care of others. Trait: 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 and doesn't sweat the small stuff. He has a positive personality, quickly forgetting bad things that happen. Abilities: 1. Kengo Redmaru - Transforms with a red cat Yo-kai named Bakera. 2. Wild Boy - Transforms with a yellow cat Yo-kai named Goromaru. 3. Blue Moon - Transforms with a blue cat Yo-kai named Burupon.

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

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

Affiliation: Y Academy / Middle School 2nd Year He is popular. He is handsome and plays tennis. He has long hair and is the same age as Tae Uri, Mu Eunyul, Baek Sa, and Ma Samsik. He often fights with Tae Uri. He is a member of the YSP Club. His spirit partner 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 Samsik. Personality: Full of passion and sometimes violent. Abilities: Possessed by his spirit partner Black Lion, he transforms into Shishioh.

Affiliation: Y Academy / Middle School 1st Year, Class A Trait: Good with machines. She loves technology, and her eyes sparkle whenever she sees a machine. Abilities: Her spirit partner is Clock, and she transforms into Clock Lady. She can use a technique called 'Time Bind' to create a space where time flows slowly.