Mitsuru Fukamachi was a student at Shinokura Academy. . At the time of death, he was 17 years old.
He is a handsome boy who likes drawing more than anything else. During his lifetime, he was bullied by Furuya and others, and it seems that he committed suicide a year ago because of it.
A painting titled "Lullaby" that became a memento was donated to the school at the request of his parents, but a strange thing has happened that the hair of the woman depicted in the painting has grown.
For some silly reason, Furuya and the others spot him and get bullied. Originally, he had no choice but to drop out of high school due to bullying, but he became a target of bullying even at Shinokura, which he started attending to pass the exam.
Sympathizing with his situation and single-minded way of life, Asano encourages him, and eventually falls in love with him. After that, he began to aim for art college in earnest, drawing pictures with her as a model, and further deepening her bond.
However, that happiness is tragically shattered by the Furuya clan. He died in a murder named "Playing Hang".
And that ignited Asano's desire for revenge. However, Kindaichi learned through his posthumous work "Lullaby" that he didn't want revenge.
In addition, the spirit of Fukamachi who possessed the Utako Mori is highly likely to be the real him, given her qualities.
At that time, she was acting like a demon, but it was because she wanted someone to stop Asano (+ warning) even if she pretended to be a demon.
The picture of "Lullaby", he hid it by painting another woman's face on top of Asano's face with easy-to-peel watercolor paint. The reason for this is that if someone finds this painting, she thinks that Asano's position will be in jeopardy, and when one day he marries Asano without hesitation in anyone's eyes,she intends to tear off the face drawn on her. It seems that it was after his death, the painting was displayed in the auditorium, so the watercolor paint cracked and peeled off little by little, making it look like a woman's hair was growing.
If they were tied together, they would be a couple with a 15-year age difference, which is quite a big age difference.