전체 에피소드

김전일(미치에다 슌스케)이 다니는 후도 고등학교에는 학원 7대 불가사의라고 불리는 수수께끼가 있었다. 그중에서도 베일에 싸인 7번째 불가사의의 비밀을 알게 된 자는, 구관 건물에 숨어 산다는 '방과 후의 마술사'에게 저주를 받고 죽는다고 한다. 미스터리 연구회의 부원인 나나세 미유키(카미시라이시 모카)는 부원들과 함께 그 비밀을 파헤치기로 한다. 그러던 어느 날 밤, 미유키는 연구회의 부장인 사쿠라기(오토모 카렌)의 호출을 받고 김전일과 함께 구관 건물에 들어선다. 하지만 그곳에서 목격한 것은 '열리지 않는 생물실' 안에서 목을 맨 사쿠라기의 모습이었다! 그 옆에는 '방과 후의 마술사'로 추정되는 자의 그림자도 보였지만, 막상 문을 부수고 들어가 보니 아무것도 없었다. 그리고 다음 날 사쿠라기의 시체가 발견된다. 켄모치 경감(사와무라 잇키)은 당시 구관 건물에 있던 사키(이와사키 타이쇼)를 비롯한 연구회 부원들과 현장에 함께 있던 숙직 직원 타치바나(스기모토 텟타), 교사 마토바(미츠이시 켄)를 모아 놓고 수사를 시작한다. 7대 불가사의에 대한 조사를 후회하는 미유키. 하지만 그 후에도 희생자는 속출하고, 결국 미유키마저...! 또한 10년 전에도 비밀을 파헤치다가 실종된 학생이 있었다는 게 밝혀지는데... 범인을 향한 분노를 감추지 못하는 김전일은 '할아버지의 이름을 걸고' 반드시 범인을 밝혀내겠다고 맹세한다. 기괴한 밀실 살인사건에 숨겨진 장렬하고 슬픈 진실은 무엇인가?

Inspector Kenmochi, Kindaichi, Miyuki, and Saki go on a fishing tour. Their destination is Seiren Island, from which an eerie sound emanates. The sound is said to be the cry of a siren, a sea creature from Greek mythology. Sirens draw people into the sea with their voices and devour them. In the evening, all the tour guests receive a letter from Dr. Kanno who came on the trip with Professor Kageo, her hospital colleague, and Izumaru, a medical equipment salesman. The tour leader, Nagita, seems to have known the doctors for quite some time, but for whatever reason is set on avoiding them. The letter asks for everyone to meet at a designated time and place. Once everyone arrives, an arrow fired from the sea hits Dr. Kanno between the eyes and kills her. The next day, a tour guest goes fishing and is dragged into the sea. Is this really the work of a siren? Kirigoe, the only inhabitant on the island, tells Kindaichi and the others about the tragic history of Seiren Island during the war.

With the news of clear weather in the morning, Kindaichi can finally leave the island where sirens' cries echo. But that night, Dr. Kageo mysteriously goes missing. Kindaichi and the others search for him on the island and find a boathouse with a locked front door. From the window of the back door, they see a man collapsed on the floor. Just then, the lights turn off in the cabin and a floating light exits. As if guided by someone, the party follow the light to find Dr. Kageo's corpse. However, at that moment, everyone on the island was gathered at the scene. Kindaichi perceives that every person was present during all three murders and he discovers a video that Saki recorded. The group is in shock when Nagita reveals an unsettling secret concerning Dr. Kageo. Meanwhile, Miyuki is worried sick about Kindaichi and has not been able to sleep. She tries to help him in her own way. Who is the killer among them?

Kindaichi and Miyuki are on a family trip to Hakuja Village. There, they run into Inspector Kenmochi, who is on the tail of a murderer. At the lodging, Kindaichi learns from the inn master, Kyoka, that the village has a tradition of worshipping white snakes as messengers of the gods. The three spot a suspicious-looking masked man entering the adjacent brewery. It is the White Snake Brewery, which has been run by the Shiragami family for generations, and which Otomatsu is currently presiding over as president. The suspicious man turns out to be Rengetsu, the Shiragamis' second son who had been missing for five years after a fire. His face and voice have changed following the fire, but a DNA test proves his lineage. Kindaichi and the others back down once the man's identity is known. The three are then given a tour around the brewery by the apprentice head brewer, Washimori, and they observe the craftsmen make sake.

Saki takes Kindaichi and Miyuki to an inn owned by his relatives. At the inn, they meet four art college students, who invite Kindaichi and the others to take part in a dare. Saki, who is rooting for Kindaichi and Miyuki to get together, convinces them to participate. The setting for the dare is a dilapidated hospital that was closed down thirty years ago. At the hospital, the art students tell them the tale of Hanako, the ghost of a patient that still dwells in one of the toilet stalls. Anyone who calls out to her is said to be killed. The dare is for each participant to go inside Hanako's stall at the very end of the bathroom, say "Hanako, let's play," then bring back a ping-pong ball from a can to prove that they did the dare. They each get ten minutes to do so. They take turns according to the lot they drew, and one by one, each participant returns. But Ino, who was the last person to go, leaves for his turn and never comes back.

Kenmochi enlists Kindaichi and Miyuki's help when a threatening letter arrives at the home of the inspector's childhood friend, Shino Tatsumi, who married into the prestigious Tatsumi family. Upon arrival at the village of Kuchinashi, they encounter armor-clad men. According to Saruhiko, a servant of the Tatsumi household, the men are taking part in a festival to appease the spirits of fallen samurai who were beheaded by the Tatsumi family in the past. The threatening letter is addressed from the Headhunting Samurai, someone thought to be holding a grudge against the family. In this village where the Headhunting Samurai roams and heads go flying, Inspector Kenmochi rises to the challenge of uncovering the secrets kept by the old family.

Kindaichi and friends visit an opera house to see a live performance of The Phantom of the Opera. Miyuki and Saki are excited to meet the famous actress Leona Kozuki, who plays the heroine. During the reception for theater members, Himori, who had left the theater company, approaches Leona, but is harshly rejected by Mikitani, a current theater company member. The other company members Izumi and Jo are also on high alert against Leona being scouted by another company. Eventually, rehearsal begins, and Izumi takes center stage under Director Kageshima's instruction. However, the very next moment, the chandelier falls down, taking Izumi's life. Shiragami, a journalist, claims that it was no accident, but the work of the Phantom who lurks within the opera house. The Phantom's shadow appears before Leona and Inspector Kenmochi, and further tragedy ensues. Kindaichi then learns about Kiryu, a prodigy actor who played the Phantom on that same stage three years ago.

Amidst a series of murders that appear to be committed by the Phantom, the same mask worn by Leona Kozuki's attacker is found in Jo's room. The members take turns safeguarding the key to the theater. However, by the time Kindaichi, Saki, and Leona enter to bring food to the lone man, they find that he has been murdered. Kindaichi's frustration grows as he struggles to solve the mystery of the locked room murder. Meanwhile, Kenmochi notices that something is amiss at the tower where the Phantom ambushed him. Kindaichi swears on his grandfather's name to uncover the true identity of the Phantom, the killer responsible for three deaths.