Tear Jerker / Detective School Q

• The case that involved Shino and the murder of her Unlucky Childhood Friend, as well as the one featuring Kyuu's childhood friend Kaoru and her Big, Screwed-Up Family, Sympathetic Murderer Mio Fuuma's heartbreaking Villainous Breakdown, the scene where Kuniko reveals herself as the victim of brutal online bullying... to the guy she used to love, and who killed someone else believing that he had driven his e-girlfriend to kill herself., and also when Ryu Takes the Bullet in Kyu's place during the case of the violinist Mitsuru Hoshou, specially after seeing him struggle hard with himself before.
• The Awful Truth behind the Ichinose Seance-Murder case. The Medium IS the supposedly deceased mother. The two brothers who thought they were protecting their baby sister have unknowingly committed MATRICIDE. And once they found out, both crossed the Despair Event Horizon right there, with one of them screaming "Mother! Mother! I killed my mother! I KILLED MY MOTHER!" since he's the one who stabbed his mother himself.
  • The aftermath of the case where Kyu found the letter Kaoru's mother left behind. Manga and anime version differs; while Kyu only showed the letter to Kaoru in the anime, Kyu showed it both to Kaoru and her brothers in the manga. The contents of the letter is the same though in both version, wishing for the siblings' happiness while saying sorry for being busy she didn't have much time as a mother. The heartbreaking part is that the letter was supposed to be given when the Seance was conducted. But since the murder and Awful Truth happens...
• There's also the case where the victim is Shino's Unlucky Childhood Friend Toujo. Megu was upset because of Shino's apparent insensitivity to this and storms off, but Kyuu convinced her to return. When they returned to the crime scene, they saw Shino covering Toujo's lifeless body with a sheet and taking care of him, which drives Megu to tears. The ending is even more tearjerker when Kyu found Toujo's painting of Shino, hinting that he may have a feeling toward her. This painfully shows viewers one of the most important rules for people working in community services like physicians and police officers; never let personal feelings get the best of yourself.
  Megu: " Katagiri-sensei... I'm sorry! I'm so sorry!"
• The killer's motive in "Psychic Murder Case". There are four people conspiring in this case. All of them were subjected to child abuse and rape from this case's victim^note Mind you, there were also two males among the murderers, that means these two were subjected to sodomy. and they couldn't escape since they were orphans without place for living except the institute. There were originally six people under the same treatment but one of them died from torture after stealing thus kickstarting their desire for revenge. These four originally wanted to ask the fifth person to go along with the plan but they couldn't because they didn't want to ruin their friend's successful life. This doubles as heartwarming since their friendship is still strong despite the hardship.
• King Hades' plan to make Ryu into his successor. It involves forcing 4 people to kill each other while bringing every one of Ryu's darkest secrets and the most traumatizing parts of his past into the light so he'll be too broken to resist leading Pluto (and even before that, they erased the first time Megu and Ryu met from the former's memory so Ryu literally was alone in the world save for Pluto agents). The lead up to this that shows just how much Ryu hates being related to Hades and how worried he is about the man's tendencies being In the Blood is heartbreaking as well; and the fact that Ryu does sometimes worry that the rest of Q-class would abandon him if they knew tugs at your heartstrings also as they're the only people in the world Ryu feels care about him as a person instead of as a pawn to be used as others see fit. No one should ever have to go through that, let alone someone Ryu's age.