Ai Haibara and Mitsuhiko Tsuburaya
 Relationship analysis
Mitsuhiko develops heavy romantic feelings for Ai, and Ai is aware of this. However, although Ai is kind to him, she does not seem to reciprocate romantic feelings for Mitsuhiko, perhaps because she is really much older and has had very different life experiences. Ai uses his feelings to her advantage when she needs him to do something, but she also admires his courage during critical situations and respects his feelings. She, in some episodes, also shows more confidence with Mitsuhiko than with Ayumi or Genta. A recurring element in Mitsuhiko and Ai's relationship is Conan; he usually secretly observes their "moments" and pokes fun at Ai's interest in Mitsuhiko while she replies with some sarcastic comments.
- This is the first time that Mitsuhiko starts showing affection for Haibara. He blushes after she explained about the legend regarding apple being the forbidden fruit. When asked by Conan why he made such a strange expression, Mitsuhiko answers that he was just looking at Haibara, as he is amazed by her intelligence, mature personalities, and mysteriousness. However, the boy gets embarrassed and denies that he has feelings for her. Conan then warns him that Haibara is not the right choice for him, since "she'll be too difficult to deal with".
- Later, when the group's spreading out to search for Genta who got lost, Haibara chooses Mitsuhiko as her partner, much to his surprise. Meanwhile, Mitsuhiko is concerned about the way Haibara and Conan usually discuss in private, about things that normal children don't understand, and wonders whether there is some kind of relationship between the two. However, Haibara states with a serious look that her relationship with Conan "is not as romantic as it seems".
- When Ai falls to the ground after twisting her ankle, Mitsuhiko immediately runs to her side and aids her by cutting his towel into strips to wrap around her ankle, just like a bandage. She is conspicuously delighted by his natural intelligence and compliments him. Mitsuhiko blushes and answers modestly that he actually learned this technique from Conan. The boy then sadly comments on how smart and knowledgeable Conan is and the fact that he can't compare himself to the young detective. Unexpected to Mitsuhiko, Haibara smiles and tells him:
|“||How silly... The most important thing is that you have this knowledge and know how to use it after learning. Right now, you're my most outstanding rescuer. Thank you for your help...||„|
- Mitsuhiko shyly blushes because of Haibara's compliments. They stand up and continue walking, with Mitsuhiko gently supports and carries her away while smiling in happiness. It is implied that Haibara's aware of his feelings for her, as she stares at his reddened face silently.
- On the ride home at the end of the case, when Haibara comments that she hates how people go over board for the sake of animals, Mitsuhiko is disheartened but is cheered up by Ayumi's more positive outlook. Haibara observes them discreetly, revealing a gentle smile. Conan notices this and smirks at Haibara, as he knows that the real reason behind her comment was to dissuade any more feelings of admiration from Mitsuhiko. Haibara realizing that Conan had caught on, blushes and she defensively asks him what he was looking at.
- On the train, when Mitsuhiko is listening to the result of the game, Haibara leans her head right next to his in order to listen to the radio. Mitsuhiko constantly blushes as she questions him about the status of the game and whether the player Ryusuke Higo is still on the field, to which he answers awkwardly. Haibara then asks him to let her know if the match starts again, and Mitsuhiko agrees with his face still red.
- At the end of the case, Haibara leaves the group and Conan suspects that she's trying to depart away from them all by taking another train. However, it turns out that she has been looking for Mitsuhiko's lost portable radio this whole time.
- When the Detective Boys find out that Mitsuhiko is leaving the city and track him down to a mountainous area in Gunma, Haibara voices her concern about his sudden and secret travel, wondering what could possibly have prompted him into having such behaviors, as Mitsuhiko has always been the serious and considerate one.
- It later turns out that Mitsuhiko went into the mountains to catch fireflies because he had overheard Ai and Ayumi talking about how pretty they were, and wanted to surprise the girls, as fireflies are symbols of summer that you can't find in the city. However, when he has finally caught one, he realizes that he must hold it with both hands, and thus unable to answer to Conan's call via the detective badge. Despite this, Mitsuhiko didn't give it up for the sake of Ai and Ayumi. Earlier, even after hearing Conan's warning that there was a serial killer nearby and that he needed to contact them immediately, Mitsuhiko refused to let go of the firefly and chose to run away from Ki'ichiro Numabuchi instead. Ai, along with Ayumi, is astonished when she learns this and asks "You did all that for us?". They express their appreciation, while Mitsuhiko blushes and smiles happily.
- At the end of the episode, Ayumi mentions to Haibara the sighting of a legendary animal, called Tsuchinoko. Both girls mention how they would like to see it. Mitsuhiko and Genta begin plotting ways to go find this creature and show it to the girls, even though this is seemingly impossible.
- Mitsuhiko pulls Ai to the top of the stairs with him so that they would become the empress and emperor in the photo.
- Mitsuhiko suggests, while blushing, that when they discover a new comet, it should be named after himself, Haibara, and Ayumi. He later adds he finds romantic that his initials, Haibara's and Ayumi's can be formed with the same number of cigarettes.
- Conan, Mitsuhiko and Genta try to release an unconscious Ran from a car. As the current gets stronger and stronger, it sends with itself Conan and the two boys. When Mitsuhiko and Genta reach the shore swimming, the current is already very strong, so Ai helps Mitsuhiko come out of the water.
- The Detective Boys look for a missing girl who is said to resemble Ai. Ayumi says that the girl is popular among the girls but not among the boys in her class. Mitsuhiko, however, blushes and says that Ai is liked even by boys. When Ai hears this, she turns around to Mitsuhiko, smiles at him and thanks. Then, after Conan has lent his cap to her, Mitsuhiko, probably wishing to compliment her, enthusiastically says it makes her look really boyish.
- Mitsuhiko grabs Ai's hand during the snowstorm to make sure she doesn't get lost, but it turns out to be Genta's hand instead.
- Later Ai shows Genta special attention when he falls into the snow and gets a nosebleed. She uses tissues to stop his nose from bleeding and holds his face while telling him to stay still. Mitsuhiko watches Ai walk away, blushes and exclaims that he's really jealous of Genta.
- The children tell one another about the horror story of a mountain witch who eats children. Mitsuhiko states that he will protect Ai and Ayumi with his life, should the mountain witch really appears. As a result, and after having thanked him, Ai smiles sarcastically and asks whether Mitsuhiko would let himself be eaten in her place, much to Mitsuhiko's awkwardness.
- They eventually find a house in the mountain to spend the night;in the threshold, Mitsuhiko searches himself for slippers to put at Ai and Ayumi's feet.
- Suspecting that one of the three arson suspects is from the Black Organization, Haibara asks Mitsuhiko to "cooperate" with her in order to get a better look at them. She puts her hands on his shoulders and tells him to walk backwards. She, while holding his blushing face, also asks him to keep his eyes on her without turning around, to which Mitsuhiko agrees. As Haibara approaches the trio, she accidentally grabs his shoulders too hard and ends up making him fall to the ground, scratching his elbow. Worrying about Mitsuhiko's condition, Haibara immediately bends down towards him. She apologizes and wonders if he is alright, but he answers, with a smile, that he's not seriously injured.
- When Mitsuhiko is kidnapped along with a young woman, Ai jumps in the car and tries to pull the ignition key to prevent his kidnapping, only to get abducted as the third hostage.
- Ai asks Mitsuhiko to do her one favour. He follows this request with pleasure.
- Mitsuhiko offers to help Haibara get up after she tripped and fell down to the ground while playing football. He also apologizes for not passing the ball properly, but she answers that it wasn't the case.
- While inside the delivery truck, the thread of Haibara's sweater gets caught on some bushes and she loses it as a result when the car starts driving away. Mitsuhiko shyly offers her his jacket to prevent her from getting cold and so that she can leave with a covered body. Unfortunately, as he only has a T-shirt left, he gradually suffers hypothermia and eventually loses consciousness not much later.
- When Mitsuhiko wakes up, he realizes that he's sharing his jacket with Haibara, who is embracing him from behind as an effort to make his body warmer. She apologizes for causing his sufferings, and suggests that he stay still so she can warm him up with the heat of her body. Mitsuhiko blushes heavily while thanking for her kindness.
- When the Detectives Boys are about to take their commemorative photo. Genta give the camera to Mitsuhiko to take their picture. But Mitsuhiko said that he wanted to be in the photo with Haibara that's why he gave the camera to Ayumi instead. But Ayumi said she wants to be in the photo that's why he gave it to Conan. When Conan was about to take the photo. Detective Takagi arrive with the police drone to take their picture as a reward for their help in solving the case. In the end the drone takes their picture with Detective Takagi on the photo.
- Mitsuhiko confides to Ran that he is in love with both Ayumi and Ai, but he wonders if that makes him a bad person. Ran advises that they should remain as good friends for the time being, to which Mitsuhiko seems to be content.
- As the Detective Boys make their escape in a sports car that they ride off the top of an exploding skyscraper, Ai suddenly falls out of her seat. However, Mitsuhiko manages to grab her hand on time, declaring that he will never let go.
- At the end of the movie, Ai walks up to Mitsuhiko and thanks him for saving her life, causing him to blush. He then states that it was only "a man's responsibility".
- When Ayumi says that she is cold, Mitsuhiko takes off his jacket and intends to give it to her. However, Ayumi has already received Conan's jacket, so he ends up passing it to Haibara instead.
- Haibara makes fun of Mitsuhiko, asking whether he wants to have a bath with her. He immediately blushes and faints to the floor.
- Ai offers to keep place for Ran and the other Detective Boys as they're standing in a queue. Mitsuhiko immediately states that he is willing to remain and wait together with her.
- Mitsuhiko constantly looks at Ai while he's singing and blushes heavily. The chorus coach tells him that's the reason why his singing was bad.
- In Conan's dream of 10 years in the future, Mitsuhiko, thinking that Haibara is going on a diet, blushes and tells her that it's not necessary since she already has a nice figure.
- When a man and a woman in black confront Ai and Ayumi with seemingly sinister intentions, Mitsuhiko quickly intervenes. He holds on the man, telling the girls to run away immediately.
- Later, Mitsuhiko dreams of being married with Ai one day.