"Opera House Murder Case" is the pilot case arc in both the File Series and the entire franchise of The Kindaichi Case Files.
Hajime Kindaichi is the picture of a typical underperforming high-school student; an unmotivated, perverted slacker and troublemaker with poor grades in his classes, a terrible aptitude for sports, and has gained the reputation amongst his peers as something of a class clown. However, behind this exterior is a brilliant mind with an IQ of 180, further honed through the stories and teachings of his grandfather, to whom he also inherits his instinct as well as his inner sense of justice - the legendary Great Detective, Kosuke Kindaichi.
When his childhood friend, Fudo High School student council president and drama club member Miyuki Nanase, brings him along to a club trip to Uta Island where the Opera House Hotel resides in order to rehearse a performance of Gaston Leroux's The Phantom of the Opera for an upcoming competition, tensions between the drama club members bubble to the surface, revolving around the death of a former member...and suddenly a gruesome series of murders occur, targeting the members of the drama club one by one. Against the reprimands of cantankerous police inspector Isamu Kenmochi, and in the presence of many other mysteries in the Opera House Hotel, can Hajime's detective skills unmask the 'Phantom' and bring the truth behind this dramatic serial killing to light?
Tropes include:
- Accidental Pervert: At one point during the case arc, Kindaichi answers to Miyuki's call to enter her room, only to find her in the midst of changing her clothes, but he's not punished for it this time because he immediately backs out of her room without lingering around for perverted purposes.
- Clock Tampering: Kindaichi, after realizing who the culprit is and what method said culprit would use for the final murder plot late in the case arc, secretly alters the culprit's wristwatch to trick said culprit into self-exposure during Summation Gathering.
- Dead Man Writing: The deceased star student penned and sent a letter to her boyfriend before she was Driven to Suicide, where she confides to the real reason behind her suicide and wishes for him to forgive the girls who were responsible for the Deadly Prank. Unfortunately, her boyfriend never saw the letter due to having never returned to his residence after her suicide and is told the truth only late in the case arc.
- Deadly Prank: The intended targets in this case are girls who, out of jealousy towards a star student in the Drama Club, carried out a prank to scare said student, only for her to bump into a cabinet in the moment of fright from said prank, and the ensuing impact caused a bottle of acid on the cabinet to fall straight down onto the student, disfiguring her face horribly as the result.
- Exact Words: Played for Laughs. After everyone arrives at the opera house, the owner introduces them to the sound system and tells them that the system still works well despite it being old. He mentions that "it just needs a little bit of cleaning", but a cloud of dust goes everywhere as he starts dusting, causing a few people to cough from the dust.
- Faking the Dead: At one point, the costume and the mask for the main character of The Phantom of the Opera are discovered out of a window of the opera house. Given the fact that the opera house is on an island surrounded by cliffs, even falling into water is not guaranteed to ensure survival. Kindaichi, however, deduces that the culprit merely tossed the costume out of the window in an attempt to pretend to be dead.
- Hanging Around: One of the victims is discovered this way, hanged by a noose on a tree. Kindaichi states during The Summation that the victim in question was killed via strangulation before being moved to the spot where the body is found, though.
- He Knows Too Much: The Drama Club adviser is killed solely for being unlucky enough to get too close toward the truth before the culprit could finish the serial murder.
- Homage: To The Phantom of the Opera, as the Drama Club members are set to rehearse for and perform it for the upcoming drama contest, but the serial murder case ends up derailing it.
- The Phantom of the Opera is not the only Gaston Leroux work to be homaged - the killer suddenly inexplicably vanishing as he is approached in multiple sides on a turn on a corridor is an impossibility taken directly from Leroux's The Mystery of the Yellow Room.
- Japanese School Club: Most of the people who are involved in this case arc are from the Fudou High School Drama Club.
- Poor Communication Kills: The culprit in this case murders the girls responsible for the Deadly Prank that horribly disfigured a star student of the theater club, who supposedly killed herself in despair. But in truth, the student had killed herself not out of despair, but because she wanted to die before she could grow to hate the girls and sent a letter to her boyfriend, the culprit, telling him about this and wanting him to also forgive them. Unfortunately, the culprit never got the letter because he didn't go back to his residence after her death and only is told the truth after he's murdered two of the girls and even their club advisor, who had nothing to do with the incident and was attacked only for being unlucky enough to get too close toward the truth.
- The Resenter: Played for Drama, as the intended targets in this case are girls who took their jealousy out on a star student in the Drama Club in a prank that ended up horribly wrong and sets the murder case in motion subsequently.
- Right Behind Me: Played for Laughs. Late in the case, Kindaichi gets Miyuki to help him test the effect of sound system communication access, with the curtain up or down on stage. The communication between them is completely fine with the curtain up, but the access actually gets blocked off with the curtain down, resulting in Miyuki returning to the sound room, where Kindaichi is. Since Kindaichi can't see or hear Miyuki because of the curtain, he assumes she's still on stage and starts teasing her, right up until Miyuki answers his question right behind him.Kindaichi: (through the sound system) Hello? Miyuki-chan, the girls who wears pink panda-bear panties? Are you there?
Miyuki: (behind Kindaichi) That's not true! I have different underwear now. - Skipping School: This case arc concludes with both Kindaichi and Miyuki playing hooky for the day. Kindaichi, however, presents a good reason for it, as he plans to deliver the letter penned by the deceased star student to the grave of the culprit, who was Driven to Suicide right as the case was ending, and Miyuki is moved into going along with him after Kindaichi invites her for it.
- Sneeze Cut: The series start out with Miyuki's peers gossiping about her and Kindaichi, followed by Kindaichi sneezing while he lazes around on the school roof.Kindaichi: Achoo! Oh, great! Someone must be talking about me.
- The Straight and Arrow Path: A crossbow is among the props that the members of the Drama Club have brought with them. The murderer intends to use it to kill the last of the targeted girls before Kindaichi talks him out of it by reminding him of the deceased star student's final words and said student's intended purpose for saying those words before her suicide, and then the murderer becomes Driven to Suicide and uses the crossbow to kill himself instead.
