Vivia is incredibly unmotivated. He is frequently tired and reluctant to cooperate with investigations, preferring to sleep or read. Vivia is near constantly melancholic, even expressing extreme emotions with a level of stoicism. He frequently proclaims his exasperation with life, expressing his wish to 'die someday.' Despite his role as a detective, Vivia has a strong aversion to the truth, adamantly believing that in some situations, the truth shouldn't be exposed at all. 

Sleepy

Muichiro is an air-headed individual who seems to constantly wander off in thought and is unable to focus on anything. Impassive and, at times, obtuse, he tends to think only for himself and operates on logic alone, never letting emotions guide him, making him seem seemingly apathetic and indifferent. he has been shown to become serious when it is required and is devoted to his position as the Demon Slayer Corps' Mist Hashira.  Alternatively he seems to display a cold and arrogant side

The mist Hashira 

Tanjiro is very kind by nature and has been described by others as having very gentle eyes and a compassionate persona. He exhibits a great deal of determination. He is very protective of his friends and even more so of his younger sister. Tanjiro is direct and very honest, taking everyone's words with sincerity and seriousness. He has difficulty lying. Tanjiro's most notable attribute is his ability to empathize with anyone, even demons.