"Murders In The Demon Dog Forest Case" is the pilot case arc in the Case series of The Kindaichi Case Files.
As Miyuki is participating in mushroom-picking for the upcoming trip that's arranged by a fellow classmate of Kindaichi and Miyuki, Kindaichi resorts to tricking and forcing his way into the expedition. Kindaichi, Miyuki, and two other classmates, one of whom has a run-down family cabin in the Yamanashi mountain, set off for the mushroom-picking, which goes wrong and soon leads them into an abandoned research laboratory building that belongs to the family of a university student. It's in this vacant building that a serial murder case ensues.
Tropes include:
- Blind Without 'Em: One of the victims in this case turns out to have poor eyesight. One of the university students informs Kindaichi that the victim tells him that he can't even walk without wearing his contact lenses. The discovery of contact lenses inside the container is among the clues that help Kindaichi to solve the case.
- The Bus Came Back: Takashi Senke, Kindachi's childhood friend from elementary school whom he helped out during the School of Hanging Necks murder, comes back in this case in his third appearance (after a cameo appearance in a short file case that marked his second appearance). This time however, he's not as innocent as he was in the last two cases - he's the "Cerberus" that sends this case's victims to their deaths.
- Dangerous Windows: Early in the development of the serial murder case, a dog jumps through a window and lands a bite in a guy's arm. The bite is not deep and the dog is repelled quickly enough, but everyone is still forced into retreating into a windowless room upon spotting no fewer than a dozen dogs growling angrily outside.
- Dude, Not Funny!: When Kindaichi asks one of the university students about a group of four undergraduate university students (two of them have already died as murder victims by then) working in a hospital, the student in question recalls an incident that occurred when he was present while the group in question was practicing human dissections, during which one of them in the group made a tasteless joke using a real human ear. All four of them in the group laughed, whereas the one witnessing it found it only cringe-worthy but could do nothing but keep his feeling of disgust to himself.
- Dying Clue: One of the victims in this case is seen placing a hand on a honeydew melon crushing a tomato while several other types of fruits litter on the floor where he lies dead. The scene is intended to clue Kindaichi in on the identity of the culprit, as Kindaichi reveals during The Summation.
- Epic Fail: Kindaichi picks some mushrooms that act as hallucinogens to make sure he'll get to have time alone with Miyuki, only to result in the consumers burning down the cabin they intend to stay within in their moment of delirium.note
- Failed a Spot Check: Invoked and weaponized by the culprit - through a casual remark made by them earlier in the day, and in the midst of all of the chaos that ensued after the first victim was found (as the stray dogs surrounded the building), none of the other surviving members gathered near the first crime scene noticed that one of their ranks is missing; as it turns out, said member had been long dead by then.
- Goofy Print Underwear: Due to Kindaichi deciding to tail Miyuki upon spotting her heading out with a travel bag in hand at the spur of the moment, he doesn't have enough time to change into proper clothing, resulting in him following her wearing only a tank-top and boxer shorts with heart images.
- Head Desk: More like "head window", but the trope is played straight otherwise, as this case arc begins with one of Miyuki's admirers banging his head on a glass window after Miyuki turns his advances down.note
- Karma Houdini: None among Kindaichi's group is shown being blamed for the fire that burns down the cabin, since the ones who actually set the cabin ablaze were under mushroom-induced delirium and have no memories of what they did under the effect, Kindaichi doesn't have the heart to point out the truth lest he incriminates himself for indirectly being responsible for the cabin fire and causes the two who are directly responsible (one is a childhood friend and the other is Miyuki) to feel guilty, and the other guy was in urgent need to defecate and didn't know what happened until he returned, by which point the cabin is already burning down.
- Laxative Prank: The one part of Kindaichi's mushroom trick that actually works as intended instead of ending up with an Epic Fail causes its consumer to need to excuse himself in order to defecate elsewhere.
- Mushroom Samba: While picking mushrooms, Kindaichi deliberately picks some that cause diarrhea (for one of the guys), make the consumer feel groggy (for the other one of the guys), or cause hallucinations (for Miyuki), in an attempt to make sure he and Miyuki will have some alone time. The result is an Epic Fail: One of the guys does end up having to defecate and leaving the place, but Miyuki, in her delirious state, sets the cabin on fire under the delusion of starting a fire in a fireplace, and the other guy, in his groggy status upon just waking up, pours petrol into the fire while trying to put it out, ending in the cabin burning down. Funnily enough, the other guy turns out to be the culprit in the murder case that ensues - while Kindaichi points out that getting drugged into burning down the cabin thanks to his shenanigans definitely wasn't in the culprit's plan, he definitely did take advantage of it to bring them to the scene of his schemes (when he was probably originally gonna just point out the hospital in a nightly mushroom foraging run).
- Not Helping Your Case: Hanging upside down in a failed bungee-jumping attempt doesn't exactly help in dispelling others' perception of "loser", resulting in Miyuki being unable to defend Kindaichi against the female classmate of hers calling him "the village idiot".
- Numerical Theme Naming: Most of the participants in this case actually have a number in their names, which one of the victims quickly notices upon seeing the map for the sleeping arrangements due to the names written down on said map.note The victim in question soon presents a question to Kindaichi with the intention of testing him, only for Kindaichi to make a comeback remark that makes it clear Kindaichi knows what the question is intended for, resulting in the victim later on leaving behind a Dying Clue in his final moment, knowing Kindaichi would be able to solve the case through it despite its cryptic presentation.
- Parental Abandonment: Fumi's debut includes her telling Hajime that her father up and left for Tibet in search of some treasure, leaving her to live with Hajime and his family.
- Remember the New Guy?: The first introduction of Fumi in the main cases, who appears at the end of this case arc, makes it sound like she was involved in Hajime's previous cases.note
- Tempting Fate:
- A female classmate of Miyuki's, after witnessing Miyuki turning down two guys, criticizes Miyuki for continuing to associate herself with Kindaichi, whom she calls "the village idiot". Miyuki tries to prop up Kindaichi... only to spot him hanging upside down outside the very window from the floor she and said classmate of hers are on at the time, as Kindaichi has made an attempt to bungee-jump from the school roof, but the stunt hit a snag. Miyuki is shocked into Stunned Silence, and her classmate reacts by asking Miyuki "Isn't it time you switch targets?".
- Kindaichi's attempt to ensure he'll have some moment alone with Miyuki by serving mushrooms that cause certain ill effects on human consumers ends up indirectly causing the cabin they intended to stay in to become burned down.
- A tragic example happened in the backstory, as the culprit was told by the lover that she would be discharged soon as she was about to go to hospital, only to wind up dead the next day.
- This Bear Was Framed: A plot-relevant example that is Played for Drama. The first two murder victims in this case arc are seen with scratch and bite marks all over their bodies, which, combined with a large group of angry dogs outside the abandoned building and an empty cage appearing to have been broken out of (said cage has a name-tag with "CERBERUS" marked on it), gives the impression that the murderer is a literal Hellhound or at least canine in nature. As Kindaichi reveals in Summation Gathering, this is all part of the culprit's ploy to deflect attention from survivors.
- Tongue-Out Insult: Fumi does this during her argument with Hajime.Hajime: You immature rascal!!!
Fumi: [with her tongue out] Bluuurrrppp! Cut that "seniority" crap. You're an old donkey with no kissing experience! - Unwitting Test Subject:
- When the culprit's lover was due to go to hospital, she ended up dead after a day. The culprit later discovered that she was treated by four undergraduate university students instead of a licensed physician, that those four got hold of a patient through the connection of the director of the hospital, who's also the father of one of the four, that those four subjected an experimental drug on the culprit's lover, which ended in failure, and that the four subsequently lied about her cause of death for their cover-up. It's these discoveries that would drive the culprit into a murderous resolve.
- One of the university students, who's among the participants in this case, informs Kindaichi after Kindaichi asks him as the serial murder is still ongoing that one of the four undergrad university students had been manufacturing drugs and tested said drugs on his under-classmates, with unpleasant side effects. Because of this knowledge of his, he firmly believes those four university students are capable of murder.
- Urine Trouble: A puppy that belongs to one of the university students jumps onto Kindaichi's back at one point... before peeing onto his shirt.
- Wounded Gazelle Gambit: Among the many things the culprit had done throughout the case to avoid suspicion on themselves was to have one of the stray dogs bite his arm after crashing through a window, causing everyone else to worry and fear that the culprit may contract rabies - in addition to forcing everyone to board up the windows.
- Your Days Are Numbered: The culprit's Love Interest confessed to have only half a year left to live. The culprit was not deterred by it, though.
