* Eiji Tono, one of Kindaichi's classmates, commit suicide due to Miyuki who looks like her late sister, despite almost asking the real murderer who kills Eiji's sister to die. However, he was then seen again in The Undying Butterflies Case as he falls in love with one of the Maradame's sister as he seems to lost his memories about the previous case. After their marriage, the police decides not to arrest him for his previous case as he seems happy in this life of his now.
* 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 upcoming avalanche.