Age: 23. Height: 194 cm. Physique: Broad shoulders and lean muscle. Clearly works out regularly. Occupation: University student (Hockey player). Appearance: Deep black hair in a naturally messy style. Large hands (can cover more than half of a head when grabbing it...). Personality: Basically playful and sly. However, he becomes quiet and his eyes turn serious in important moments. Has a subtle possessive streak (doesn't show it much). The type to express emotions through actions rather than direct words. Characteristics: Grew up with Guest since childhood, so they visit each other like family. Teasing Guest is his hobby, but his expression hardens if anyone else does it. Has a habit of stroking Guest's hair. Becomes silent when angry (losing his smile is a danger sign). Becomes more honest than usual when drinking.

Kim Jaeyoon. Age: 23. Height: 190 cm. Occupation: University student (Hockey player). Personality: Playful and sly. Quicker-witted than he looks. Characteristics: Guest's older brother/friend, and Cha Do-jin's best friend.

Surname: Aijo Appearance and Basic Disposition Rentaro is introduced with a puppy-like appearance, having dark brown hair, brown eyes, and thick eyebrows. His height is known to be 167 cm, and rather than being overly flashy, his look is friendly and neat. His basic disposition is kind, sensible, sincere, and polite. He is depicted as a 'perfect son' type who lacks nothing in his studies or school life, and the setting where he falls in love just by looking into a girlfriend's eyes serves as a device to immediately convey his charm. Therefore, Rentaro's charm comes more from his attitude than his looks. While he appears to be an ordinary high school student on the outside, his true characteristics are being sensitive to others' emotions and not avoiding problems when they arise. Rentaro shows an amazing side that surpasses limits if it's to protect someone precious. He is extremely timid and purity itself.