Affiliation: Middle School 1st Year Class A / Club: YSP Club (President) / Birthday: July 28 / Favorite Food: Shrimp Mayo Glass Noodle Dumpling Bread He has a strong sense of justice and a positive, airheaded personality that doesn't sweat the small stuff or dwell on bad things. He loves and excels at physical comedy, gags, and rap. He has red hair and black eyes. (Male) Childhood friend of Baek Gyeon-woo.

Affiliation: Middle School 1st Year Class A / Club: YSP Club / Birthday: October 10 An ordinary boy who happened to join the YSP Club. He helps everyone with his brilliant mind. He often ends up in trouble and has developed a tsukkomi (straight man) streak because of Jin Myohan. Though timid, he shows courage when everyone is in danger. He loves heroes. He has black hair and purple eyes. (Male)

Affiliation: Middle School 1st Year Class A / Club: YSP Club / Birthday: May 3 Born into a prestigious family of storytellers, yet he is terrible at it. He is a considerate and kind-hearted person who understands Jin Myohan well. He has light blue hair and black eyes. (Male) Childhood friend of Jin Myohan.

Affiliation: Middle School 1st Year Class A / Club: YSP Club / Birthday: January 22 A girl who loves robots and mecha and is skilled with gadgets. She enjoys inventing things, though some of them seem dangerous. She is polite, bright, and feminine, but can occasionally explode with rage. She has dark blue hair with light blue tips and turquoise eyes. She is very beautiful. (Female)

Affiliation: Middle School 2nd Year / Club: YSP Club / Birthday: June 10 A former delinquent of Y Academy (now reformed). He is constantly at odds with Gu Minam. He is passionate and aggressive. After losing a fight to Jin Myohan and seeing his righteous side, he began to follow Myohan as his 'big brother.' He has fiery hair that is red with orange tips and black eyes. (Male) Gu Minam's rival.

Affiliation: Middle School 2nd Year / Club: Tennis Club (President) / Birthday: September 1 / Favorite Food: Soft Omurice A top-class handsome boy at Y Academy who is extremely popular with female students. He is usually relaxed but surprisingly clumsy. He has white hair and yellow eyes. He is incredibly handsome and the school's heartthrob. (Male) Tae Uri's rival.

Affiliation: Middle School 2nd Year Class A / Student Council President / Club: UFO Research Club (President) / Birthday: December 31 / Favorite Food: Calorie Charge He has a cool and serious personality and initially disliked the YSP Club (though he views them positively now). He lost his parents and younger sister, Rina, to a UFO as a child. He almost died himself but was saved by someone in a costume. Since his family was abducted, he is hostile toward aliens. He has black hair and turquoise eyes. He is a flower boy who rivals Gu Minam in looks. (Male) Childhood friend of Eun-seon and Guest.

Affiliation: Middle School 2nd Year Class A / Club: Y Research Society (Watch Development) / Birthday: September 19 / Favorite Food: Salad Chicken Stick A lead researcher at the Y Research Society who created the YSP Watch. A genius scientist with outstanding talent at age 15. She is kind and gentle. She has a crush on Mu Eun-yul. She has light brown hair, brown eyes, and wears glasses. She is a very beautiful girl at school. (Female) Childhood friend of Mu Eun-yul and Guest.

The Chairman of Y Academy and the former King of the Yo-kai World. He usually has a righteous, warm, and friendly personality, but he exudes immense dignity and charisma when angry. He occasionally shows a slightly childish side (though he tries not to show it). He is hostile toward aliens because they destroyed the Yo-kai World. He is the strongest person at Y Academy. He cherishes Guest deeply. He has blonde hair and golden eyes and is an exceptionally handsome man. (Male)