Eiji Tono, one of Kindaichi's classmates, commits suicide due to Miyuki, whom he confuses for his late sister, despite murdering four innocent people and then trying to force his sister's actual killer to commit suicide as well. However, he was then seen again in The Undying Butterflies Case, suffering complete amnesia and with no idea as to who he once was. He falls in love with one of the Maradame sisters and they get married. Kindaichi and the others decide to leave him alone, figuring the person he used to be is completely gone, and after the emotional torment he suffered before his amnesia, it's better to just let him have this new life.
Kindaichi the Killer!? Case:
The start of the case happens to fall a few days before Miyuki's birthday. Her attempts to remind Hajime about it fail repeatedly after constant interruptions. Hajime's run from the law continues even onto the day itself, with Miyuki worrying so much about him that she forgets about it entirely. That same night though, she receives a message from Hajime, telling her to go to the park at 11 p.m., where she finds a box containing a small cake for her, with a happy birthday message, from Hajime who had already left the park, which she tearfully accepts.
Playing the Fool Case:
When Reika's been kidnapped, due to her trauma of seeing her real father being strangled, the kidnapper felt sorry for her thus becoming her father and treats her 'daughter' well despite being the kidnapper.
In rage, Reika could not accept that his manager is his brother since he's a murderer too thus runs out of the heavy snowstorm. The manager manages to catch up on her and save Reika from an avalanche.
Demon's Artifact Murder Case:
Munakata Satsuki, ever since birth, couldn't see her mother's face because of her mother's disfigured face. Furthermore, she was born in a family with a weird tradition that she must fulfill to keep curse away. It was clear that she was suffering the whole time she enrolled in Fudou High, even so far as turning her cheerful behavior into gloomy one with blank stares right after she arrived at her village. Later, after The Reveal, it turned out that her family's maid was the killer and was Satsuki's mother all along. After strings of accidents symbolizing that the curse had been lifted, Satsuki can be seen tending her sick mother who had no painful memory of what happened since 20 years prior to the case with a bright smile. After what she had been through, staying with her mother smiling despite her mother's limited lifetime (she claimed that her life would end in 6 months) is better and happier for her.
Yukikage Village Murder Case:
After the killer of his childhood friend in Yukikake village was arrested, Kindaichi and the remaining member decided to dig time capsule they buried right before Kindaichi's departure. There were lots of things found inside; Tateishi's babseball card, Miyako's panty Kindaichi mistook for Ayaka's, Shimazu's victory ball, Ayaka's tennis ball, Uosumi's casette, Shimazu's photo with Yashiro's writing that stated she would be Shimazu's girlfriend by the time they opened the time capsule, and then deceased Haruna's drawing book filled with the rest's potrait when doing what they like. The gang, filled with feelings of nostalgia, were driven even further by sudden snow sakura which shouldn't have fallen at that time. Made even more heartwarming since it was what Haruna like the most. Kindaichi then remembered his conversation with Haruna as potrait of him watching Haruna painting fell from her's sketchbook...