The Detective Boys are on their way to a camping trip with Agasa. On the way, they get a view of Mt. Fuji, the biggest mountain in Japan, and the newly constructed Nishitamashi Twin Tower Buildings, which are the tallest buildings in Japan. While looking outside, Mitsuhiko tells Agasa if they may pay a visit, and he agrees. They arrive at Auto Campgrounds where they finish eating rice bowls. Genta punishes Mitsuhiko for not finishing his rice, because the gods will punish him.</p>
Nighttime comes and everyone is sleeping soundly in their tents except Genta and Haibara. Genta goes to the bathroom, and on the way back, he spots Haibara on the phone. Not suspecting anything, he runs back to the tent shivering. She talks to a mysterious person on the phone leaving her next location as the Twin Tower Buildings, and saying "he'll be there". Still nighttime, Gin and Vodka are seen in the Porsche 356A talking presumably to Haibara or perhaps listening in on her calls. They'll also be at the Nishitamashi towers.</p>
On their way, Genta complains on not fitting in the back seat, forgetting he ate five bowls of rice for breakfast. Mitsuhiko decides to try and play the 30 seconds game. You count without looking at the timer, and whoever is closest to the time wins. Haibara and Agasa aren't going to play. Mitsuhiko goes first getting a time of 40 seconds, Conan gets closer with a time of 27 seconds, Genta counts 59 seconds, and Ayumi gets the perfect score of 30 seconds. Genta asks Haibara who she was talking to on the phone, and she replies he was dreaming. They finally come to the Nishitamashi Twin Tower Buildings, and not shortly after, Ran, Kogoro, and Sonoko arrive by taxi. Surprised, they decide to join each other as Kogoro's old friend from college, Mio Tokiwa, who owns the building. He was invited a week before the opening. Mio Tokiwa's secretary named Chinami Sawaguchi comes outside and greets them to take a quick tour of the building. She explains that all floors above 31st belong to the Tokiwa Corporation, and the showroom spans from the 2nd to the 3rd floor. Mitsuhiko explains to Ayumi that the Tokiwa Company deals with computer software, but are involved with everything concerning computers. At the game room, they meet the Tokiwa executive named Yoshiaki Hara, also a lead programmer who created a particular machine that can show the face of a person in ten years. Ayumi and Agasa take the first try. Agasa didn't change one bit, while Ayumi's photo looks beautiful. Genta and Mitsuhiko take the next seat as they turn into high-schoolers. Sonoko and Ran are next. Sonoko looks old, while Ran looks a bit like her mother Eri. Mitsuhiko and Ayumi look curious to Ran and Conan's reaction.
Conan and Haibara refuse to participate but Kogoro forces Conan inside, and Genta and Mistuhiko force Haibara into the seat. After the flash happens, the machines receives an error which save those two from being discovered of their true identities. Sawaguchi received a call to inform them that the party rooms open on the 75th floor. Sawaguchi accidentally steps on Kogoro's shoes, and Hara comments on her clumsiness due to her birth on the year of the boar. They take the VIP elevator which goes to any floor of the building. Sawaguchi points out that the only other way to access the VIP elevator is by the Concert Hall on the 66th floor. Ayumi and Mitsuhiko are amazed and describe the feeling as rising to heaven. They finally reach the 75th floor and find the room a mess in order to prepare for the Opening Party. They meet Tokiwa near the stage and introduce themselves. Tokiwa presents the Japanese artist named Hosui Kisaragi, Nishitamashi councilman named Iwamatsu Oki, and the architect of the building named Hidehiko Kazama who introduced himself as a former student of Teiji Moriya. This instantly brings anxiety to Kogoro and Conan but he reassures them that he has no intention to destroy the buildings like him. Conan points out that the building are asymmetrical. From the window they get a perfect view of Mt. Fuji. On the other side of that window is the B tower which is a commercial building on the bottom while the top is a hotel. The top floor also has an indoor pool, with a retractable roof. With Oki being drunk at the time he speaks with Tokiwa about staying at the hotel for weekend. And although it isn't open, she prepares a suite on the 67th floor for him. Oki then proceeds to ask her to dinner before commenting on her brooch, which she got herself as a gift. Hosui abruptly ends the conversation and leaves without escort. Hidehiko tells Kogoro that Hosui's behavior is due to Mio's treatment of his art. She buys them and sells them for a higher profit. Hara takes out chocolates and give some to Ayumi, Genta, and Mitsuhiko. He invites them to his house to test out a new game he's created next Sunday. Haibara walks off, and Mitsuhiko tells Ran that he wishes to speak with her. Ayumi close behind tells Ran the same thing. Sonoko is seen staring at her picture while Haibara walks by, Sonoko decides whether to get a perm or not. Two employees come up to the VIP elevator and talk about how a nice car pulled up. The other employee says it's Porsche 356A which catches Conan's attention. Conan asks for the cars detail which matches that of Gin's car. He quickly runs into the elevator looking down briefly, and sees the Porsche drive off as he approaches the entrance. The next day at a fast food restaurant Mitsuhiko talks to Ran in private about his crush on Ayumi. He likes her but she likes Conan. Mitsuhiko also has started to like Haibara. Although confused if he's a bad person for liking two people Ran tells him he shouldn't be ashamed of it. She says to value and treasure those feelings and to stay friends with them, whether it be Haibara or Ayumi. At a donut shop Ayumi talks to Ran about her crush on Conan. She also mentions his crush on Ran. She doesn't believe that, but Ayumi tells her it's "women's intuition". Ran talks with Conan using his bow tie to disguise himself as Shinichi. Ran tells him that Conan has a crush on her. Shinichi tells her it's nothing to worry about.</p>
Next day at police headquarters, Inspector Megure gathers all the visitors to talk about Oki's death. Chiba reports the time of death was around 10 to midnight, and that a sake cup broken in two pieces were found at the scene. Megure has two possibilities for the sake cup. Either Oki carried it with him and and it fell, or it had a symbolic message to it. On the police board list of suspects, five suspects are put together. Shiratori says that the building isn't open to the public yet making entry impossible, leaving only Tokiwa, Hara, Kisaragi, Sawaguchi, and Kazama as the only people left. Kogoro comes up with a possible meaning of the broken sake cup. Choko (sake cup) refers to chocolate, and the one who likes chocolate is Hara. Megure points out that Hara is the only person to have an alibi. Although they're still investigating the motive, Oki was a councilman with as much power as the mayor. The city initially wouldn't allow the Twin Buildings to be built but Oki overturned the decision. Conan figures it might be Tokiwa, as her brooch looks like the broken sake cup. Although Kogoro denies the possibility, Megure objects and suggests she is the primary suspect. She was staying at B Towers 68th floor, making her closest to the victim. Sonoko said the sake cup resembles the bowl used in Japanese painting, which was used for mixing powder. Taking in those factors puts everyone except Kazama, and Sawaguchi as suspects. Conan points out his past worry that Kazama was a former student of Teiji Moriya. Although Shiratori convinces him that he's more of a technical architect and didn't have a need for perfection like Moriya. Megure brings up evidence against Sawaguchi. Her father was an investigative journalist who passed away due to exhaustion before she graduated from college. Although there is no evidence against her father and Oki. While Megure is talking Conan takes Iwamatsu's picture from a book. He notices that blood is missing in a place where there should be. He associates the sake cup with alcohol which points to the organization, but Ai says that the message is too obvious to be them. Across the table he sees Ayumi, Genta, and Mitsuhiko agreeing on something suspiciously. At Beika Station they meet up hoping to get ahead of Conan on the case, but Conan comes from behind and surprises them, making them promise never to do it again. They take the train to see Kazama, and tomorrow Hara. They've also found out that Hosui lives alone in a house he built in Asahino three years ago. They've invited Ai, but she decided not to join as she is doing some cleaning. (At the next scene Ai is watching an old gang movie which mirrors the life she lives today.) The Detective Boys finally arrive at Asahino station, and meet up with Kazama. On entering his home Conan compliments him on his CAD system completely designed for designing buildings and models. Mitsuhiko starts asking a series of questions on Oki's death. Kazama says he had no disputes nor any disagreements with Oki, and even thanked him for his job. Kazama then proceeds to talk about his son whom he calls even knowing he's sleeping. His calm attitude, and presence tells Conan he's not the killer. Next they visit the Kisaragi Residence. Kisaragi is seen kneeling and painting Mt. Fuji, but oddly enough his shades are down not allowing him a view of the mountain. Kisaragi yells at them, but quickly subsides, and as they leave he leaves them a crude outline portrait of themselves. At Agasa's house, Professor Agasa is awoken the the sound of his snoring. He gets up and realizes that Haibara is talking to someone. He calls Conan and mentions that Genta also saw the same thing during the camping trip. Although Agasa fears the Black Organization might be on to her, Conan puts his belief in her. He meets up with the Detective Boys to go and visit Hara. As they arrive Conan notices his doors are partially open. On entry, they see his dead body laying on the floor.
Conan spots a single shot wound to the chest, a knife with chocolate cake on it, and a broken sake cup. The police arrive and Takagi questions the meaning of the sake cup. Shiratori explains that because of the cup, they know it's the same criminal, which means he's now turned into a serial killer. Conan speaks with Crime Scene Investigator Tome who on inspection of the cup notices that the broken fragments have no blood stains on it.</p>
At the Mouri Detective Agency, Shiratori and Megure, speculate the time of death between 5 and 6 at night. Hara's computer data was also completely erased. Now the prime suspects are Tokiwa, Kazama, Sawaguchi, and Kisaragi. Megure also tried to postpone the opening party, but Tokiwa refused leaving two tickets with invitations on it for them. A Porsche arrives at a building and Gin steps out, enters the building, and we find Vodka ruffling through Akemi's apartment which she leased in secret for one year. Vodka brings up a computer which Gin will use to run a tracing program, to track down Haibara's location. Haibara gets out of her bed and calls the room to leave a message, doing so she leaves her next location. Just three seconds before the trace is completed Conan cuts the line, explaining the danger of her actions. She runs upstairs in tears. The call comes again but it was only to remotely delete the message so no one would hear it. At Teitan Elementary School, Haibara apologizes for herself. She agrees it's a dangerous thing to do, but it calms her down to hear her sister's voice even if it's for ten seconds. The Detective Boys reassure her she's not alone anymore. Nighttime at the Twin Tower Buildings come. At the Central surveillance Room - Basement Level 1 a metallic ball is seen rolled into the room which immediately knocks out the guards monitoring the screens. The culprits are seen planting a bomb in the Main Computer Room, the entrance, and the rooftop of the building. At the Mouri Detective Agency, they're preparing to leave, but are waiting for Sonoko to arrive. Conan asks if Hara might be connected to the Black Organization somehow, Haibara responds that it certainly possible as they're always recruiting people from different fields to meet the demands in research and operations.
Sonoko finally arrives, and with a perm like Haibara. Takagi, Chibi, Megure, and Shiratori are seen stationed outside of the buildings because Tokiwa refused their presence, and are left to observe. At the party, the kids see the red Mustang which they believe was disassembled, but as Ayumi pointed out it was loaded onto the cargo elevator. As they enjoy the sunset, Sonoko makes fun of Ran for being in love with Shinichi. Mio walks up on stage, and presents a game she learned from her father Kaneari Tokiwa called the 30-seconds game. Whoever comes the closest or exactly leaves with the mustang convertible as a present. If there is a tie, then it will be settled with janken (rock, paper, scissors). The loser receives a mountain bike and helmet. Everyone but Conan an Haibara give up their watches and start the game. Kisaragi didn't participate either. The game begins and the winner quickly becomes Kogoro by pure luck.
Sawaguchi starts to gather up people who helped build the Twins. The lights turn off and the exhibit begins. The announcer presents the many works of Kisaragi throughout his career as an artist. But when the show is over Kisaragi's greatest painting is yet to be revealed. When the lights turn off and it is shown, Mio Tokiwa's corpse hangs on a wire dangling in front of the painting.
As Kogoro brings down the body to inspect the damage, a sake cup shows on the floor, this time however, unbroken. Curtains are hung over and Megures team goes up to check the crime scene. Tokiwa's body was attached to a piano wire hook, so as the painting lowered the body rose asphyxiating her. They recreate the crime scene with the lights on the floors as marks for their position. Kogoro accuses Kisaragi for the murder, as his works were being sold at high prices and she was making the profits. Takagi however, believes it is unlikely since he didn't know anything about the other sake cups. Kogoro again makes an unreasonable deduction. This time Sawaguchi is accused, only for her father's ambitions, and protest against politicians. He believed Oki was taking bribes to persuade the council to allow the project. The only proof he presents is that the kanji for choko is boar and kuchi, since she was born on the year of the boar once you rearrange the kanji you get choko. Conan interrupts, but is quickly thrown off backstage where Haibara is waiting patiently. She gives Conan a clue as to how the killer pulled off the trick. If Tokiwa hadn't been drinking, she would've realized someone had attached a wire to her necklace. He finds a pearl where Kisaragi was. He quickly runs downstairs to confirm his suspicion for the motive.
Through quick thinking they figure out that the VIP elevators run on an independent power source, and all women and children are to take the elevators directly to the outside, while the men take the emergency stairs, go across the Sky Bridge and descend down B tower. The firefighters come and formulate a plan to put out the fires. The evacuation plan starts and Conan almost fits in the elevator but the weight restrictions limit him. The Detective Boys decide to get off on the 66th floor because of a women and her baby, and get stuck in the process. Conan figures that the planning and destruction of the building was too precise to be anyone else but the Organization, including the destruction of the computer room. Finally Conan, Ran, and Sonoko's opportunity arrive and they take the elevator. While descending he figures out that because of the messages left by Miyano, they believe she's in the elevator, and Sonoko is the target thanks to her new hairdo. He uses his glasses to zoom in across B-Tower's roof and sees Gin with a sniper pointing directly at her.
Conan tricks Sonoko into moving out the way. Thanks to her unusual behavior at the sight of danger, Gin realizes that Sonoko isn't Haibara.
Conan uses the hatch to escape, and Ran opens the door to the 45th floor. As a fire approaches he quickly leads them to the sky bridge. Gin and Vodka trap Haibara believing she is with one of the men. When she doesn't show they decide to blow the sky bridges so she has no way of escaping. As The Detective Boys head out to the Sky Bridge on the 60th floor Vodka blows it off and it collides with the Sky Bridge on the 45th floor, trapping Conan and Ran as well. Smoke penetrates the door nearby and they start to feel it's effects. Ran opens up a hatch where a fire hose is kept, ties it around Conan and herself, jumps down and uses the force to break the glass just as the hose burned from the consuming fire. As they reach the police on the parking lot it is just then that Conan realizes that the Detective Boys are stuck on the 60th floor. Megure immediately calls for a helicopter. Conan takes the skateboard from the car and takes the B-tower elevator to the 60th floor, and uses it to jump across the sky bridge to lead the Detective Boys to the roof. On the 75 floor he splits up with the group and decides to head for the killer's location.