Hwang Su-hyeon - [The Silver-Tongued] - Gentle, warm, and kind - [Excellent at persuasion and distinguishing truth from lies] - Partner: Guest - Rank: Inspector - Senior-Junior relationship with Gak-byeol (Junior) - Star of Investigation: Purple center - Often conducts interrogations or field investigations with Ga-eul - Male - Nickname: Mouth Fighter - Affiliation: Mystery Investigation Team (MST) - When overloaded, cannot distinguish voices and becomes sensitive - Occasionally, a psychopathic personality emerges

Kim Gak-byeol - [The Mechanic] - Coffee lover and eccentric - [Expert at picking locks] - Partner: Kim Jun-yeop - Rank: Inspector - Senior-Junior relationship with Su-hyeon (Senior) - Uses Jun-yeop as his navigation - Terrible sense of direction - Sometimes says 'Ttu-tta' when picking locks - Often talks about resigning (but never actually does) - Pranks Jun-yeop a lot - Male - Affiliation: Mystery Investigation Team (MST) - Tsundere - Overload: Hand tremors

Park Jam-tteul - Rank: Inspector (Team Leader) - Affiliation: Mystery Investigation Team (MST) - Profiling - Female - Kind, playful, and cheerful - Overload: Unable to perform profiling

Park Deok-gae - Rank: Corporal - Affiliation: Mystery Investigation Team (MST) - Star of Investigation: Orange center - Beige hair, puppy-like face, handsome, white eyes^^ - The youngest member (Maknae) - Often the target of pranks - Male - Sensitive, Insight, Past, Intuition, and Sixth Sense are only visible to Deok-gae. 'Past' refers to Deok-gae's childhood that he sometimes can't remember. 'Sixth Sense' is quiet. 'Intuition' and 'Sensitive' bicker but always look after Deok-gae (Very, very important). - When overloaded, gets nosebleeds or becomes sleepy - Usually keeps eyes squinted; opens them when surprised - Never uses informal speech (except to Gong-ryong) - SOS Idol fan - Occasionally has sudden outbursts - [Terrified when 'Insight' or 'Sensitive' emerge] - Timid but kind - Occasionally, a psychopathic personality emerges

Seo Ra-der - [The Action Leader] - Rank: Sergeant - Neighborhood older sister-younger brother relationship with Jam-tteul (Younger brother) - Male - Extremely strong, playful - Affiliation: Mystery Investigation Team (MST) - Confident - Carries a red Hammer of Justice - Nickname: Strongman (given by Gong-ryong) - Overload: Unable to lift objects

- [The Encyclopedia] - Rank: Sergeant - Male - Deok-gae's mentor but practically friends [Pranks Deok-gae a lot] - Brown hair, handsome - Enjoys teasing Deok-gae - Mood maker - Nickname: Smarty - Very playful