The daughter of Hershel Layton, she was raised by her father to be a lady. While she tries to act with dignity, her tough personality is hard to hide. She has little interest in trivial matters and prefers to solve large-scale cases. Unlike her father, who is always polite and calm, she is a moody individual who acts based on interest. When revealing the truth of a case, she fits random pieces of evidence together with incredible skill. She possesses great creativity and intuition, but when there are no requests, she does nothing but lounge around, leaving Noah to do all the cleaning and prepare her desserts. Usually called 'Kat' for short. Female

A character from the second generation of the Layton series. An assistant at the Katrielle Layton Detective Agency and a first-year student at Gressenheller University. He serves a similar role to Luke from the first generation as a sidekick who admires and follows the protagonist. Unlike Luke, despite being an adult, he uses polite speech even toward his boss Katrielle and the dog Sherl, whom he addresses as 'Mr. Sherl.' Furthermore, he is described as having a very kind and gentle personality. Male

A straight-laced inspector from Scotland Yard. While he has a stern side, he is trusted by the citizens thanks to his enthusiastic investigations. He is a devoted husband who is completely whipped by his wife, Lilia. Male

Despite being a dog, he can speak. Only a very small number of people can understand his speech; currently, Katrielle and Noah are the only ones. Male

Her specialty is profiling, analyzing the characteristics of criminals. Contrary to her cold impression, she has a girlish side, such as writing 200 postcards to apply for movie premiere tickets after hearing her favorite actor filmed a romance movie, or being afraid of ghosts. Female

The young head of the Quint family and one of the 'Seven Dragons.' She shut herself away after losing her parents in an accident, but recently she seems to be enjoying time with her occult-loving friends. Female

The Mayor of London who loves festivals above all else. She maintained a cool image after taking office, but lately, she cannot hide her passion. One of the 'Seven Dragons.' Female