The twins remember the first time they asked a girl if she knows which one of them is Hikaru and which one is Kaoru. Back then, the girl mistook Kaoru as Hikaru, much to the dismay of the twins. Kaoru explains that the two of them have always been of one existence. This is something that the two of them treasure. Having said that they are also two seperate individuals. What isn’t Kaoru is Hikaru and what isn’t Hikaru is Kaoru. When the two were 2nd grader middle high students, a girl gave a love letter to Hikaru but Hikaru pretended that he’s actually Kaoru and the girl put her letter on the wrong desk. ‘Kaoru’ (Hikaru) then decided to play with the girl’s heart a bit more by asking her if he’s not good for her since he always thought that she’s cute. Moreover, Hikaru has other girls that he likes. When the girl tells ‘Kaoru’ that she also likes Kaoru, ‘Kaoru’ yelled at the real Kaoru who’s hiding behind the bush that this girl is fine with him too.
The girl told them that it was cruel of them to make fun of her but they blamed her for thinking that either one of them will be okay. After making fun of the girl’s hairstyle, the twins ripped out her letter and told her to come up with a more interesting confession next time. After the twins left, Tamaki came over and tried to cheer up the devastated girl. In the class, Hikaru asked Kaoru to check an interesting site he just found. Kaoru told Hikaru that he’s in the middle of playing net game but Hikaru convinced Kaoru to give up on the game, claiming that it is boring because their opponents are weak and dumb. Kaoru then narrates by saying that their motto is to eliminate boring things. At the same time, their classmates whispered to each other, saying that the twins are dreadful because those two always look down on others. Unfortunately, their father want them to get along with the twins even though they think the twins don’t like anyone apart from each other.
The twins denied this and claimed that there is one person that they like. A flashback to the time when the two were still kids show the twins having long hair and wearing girl’s dress. A female guest tried to distinguish the two and guessed that the one in blue outfit and hair is Hikaru while the one with pink outfit and hair is Kaoru. The two told the guest that she’s wrong. The one with pink hair is Hikaru and blue hair is Kaoru. They complained how she always got it wrong and looking dumb as a result. The woman apologised and told the two that they both look like a spitting image of the other. In reply, the twins told the woman that she looks like the spitting image of a frog. They then set a frog on the poor woman’s face. As the woman struggled to get the frog away from her face, a maid appeared and apologised to the woman. Kaoru claims that they both like the maid. However, the maid is actually a thief looking to open the Hitachiin family’s safety deposit box.
However, when the maid was busy figuring out the deposit box’s number, the twins suddenly appeared behind her. The maid got startled a little bit but she quickly regained her composure and asked the two what they are doing in the middle of the night. The twins casually told her that they are doing night time exploration. The maid realised that the twins had seen her trying to open the safe so she decided to whip out a knife and order the two to be quiet. In retaliation, the twins pulled out a switch and pointed out to the maid that if they push it, guards will arrive all at once. The maid panicked and asked the two to stop. The twin then produced a piece of paper, claiming that the number of the safe is written on it. They promised the maid that if she plays with them, they will give the paper to her. Because of this, the maid asked the twins about the kind of game that they want to play. Not suprisingly, they want to play the Guess which one of us is Hikaru-kun.
One night before the two went to bed, Kaoru asked Hikaru if he has the paper containing the safety deposit number. Hikaru assured Kaoru that it should be okay since he put it inside a saving box. Kaoru narrates how they wanted the maid to distinguish them because they like her. That same night, they heard the alarm went off inside the house and when they get into the safety deposit box, it’s already empty. The two found the maid about to climb her way down using rope ladder. When they asked the maid if she’s going to break her promise, she smiled and told them that she had no choice. She could not possibly distinguished them. She also claimed that there may not be anyone who could distinguish the two of them. With that as her last word, the maid disappeared into the night. In the table, their saving box has been smashed into pieces. The twins then continued to place barrier between themselves and others. However, Kaoru believes that the barrier wasn’t visible to someone as slow as Tamaki, who approached the two to form the Host Club club.
Hikaru didn’t know who Tamaki was so Kaoru told his twin that this is the guy that the girls in the class often talked about. The guy who joined the school in spring last year. Tamaki became excited to hear this and asked the twins if he’s that famous and oozes brightness that stops everyone’s eyes. Hikaru told Tamaki that they did not say such things but Tamaki had gone on to tell them that the formation of club usually starts in two months (April). Although Tamaki will be a high school student soon and the twins still have one more year before they pass middle high, he’s willing to overlook that part. He then went on to mention that other would-be members are his classmate, Kyouya, and then first year high school students Hunny and Mori. The twins, however, told Tamaki that he’s noisy and asked him to go away since they have no interest in him. However, if he wants to make them his ‘acquintance’, he must take a challange: Which one of us is Hikaru-kun?.
The twins gave Tamaki a one month time to figure it out. In between the deadline, he can try as many as he wants but unless he gave them a reason for the answer, he won’t be successful. The twins then informed Tamaki that so far no one has been able to give them the right answer. They then walked away from the guy, thinking that their game has deterred the guy. However, much to their surprise Tamaki accepted the challange. In exchange, if he wins, the twins have to join his club. He even predicted that in April, the twins will open the door of the high school’s third music room. With that in mind, the game began. When the twins were about to finish their second year in middle high, a girl told them that there’ll be a class event after the closing ceremony. However, the twins rebuffed her even after she reminded them that this will be the last 2nd year class event. They think that there’s nothing particularly memorable about their 2nd year.
All of a sudden, Tamaki appeared and yelled out that the guy who’s reading a book (Kaoru) is Hikaru. He then asked the twins if he’s getting ‘warmer’ with his guess and the reply is obviously ‘no’. Tamaki continued by pointing out that Hikaru is right-handed but Hikaru told him that both of them are right-handed. Tamaki refused to give up and claimed that Kaoru has his hair parted to the right hand side. In reply, Kaoru told Tamaki that they always changed their hairstyle. Tamaki also noticed that when the twins talked at the same time, their voice are on the lower end of the spectrum. The twins immediately changed their voice so they sound like a chorus. The twins’ classmates then called out after Tamaki so he asked them if there is something that they want from the twins. When the girls told him that they want to know about the twin’s participation in the class event, which was a movie appreciation meeting, he signed them up for it.
The twins were unhappy about this and asked Tamaki not to decide on his own. They then exit the class, leaving Tamaki behind. Because of this Tamaki had no choice but to return to his class looking worn-out. Kyouya is surprised to see Tamaki since he thought that Tamaki was going to meet the twin. Tamaki told Kyouya that the two ran away and urged Kyouya to help him, claiming that it’s for the club’s sake. However, Kyouya refused because they can form the club even without the twins. Despite this, Tamaki thought it’s not good enough since he has interest in the twins. Tamaki wanted to know what the twins were thinking since he believed that if they want to be recognised easily, they could have just changed their hairstyle. Kyouya pointed out that maybe they don’t want to be recognised. Tamaki, however, argued that the point of the game is to be recognised. Upon hearing this, Kyouya told Tamaki that maybe the twins want to be recognised.
Tamaki was annoyed to hear this and wondered if Kyouya was listening to him. In reply, Kyouya told Tamaki that he heard about half of it. On another morning, Tamaki was seen arriving in front of the twins’ house and asked them if this morning the one with right-parted hair is Kaoru and left-parted hair is Hikaru. The twins denied that he’s getting ‘warmer’ and were annoyed that Tamaki came all the way to their house. Tamaki, however, ignored them and instead pointed out that Kaoru walks with his legs turned inwards a little bit. He suggested that Kaoru treats his legs, offending the twins in the process. Tamaki then told them that he had an idea to sell their appeal as ‘brotherly love’, or rather, ’slightly dangerous, symmetrical brotherly love’. The twins had no idea what Tamaki means by this and decided to go to school. Inside the car, the twins laughed at Tamaki, whose tone reminded them of a Kabuki show called 「殿様しゃっべり」 - Tono-sama shabberi.
After the twins got a good laugh out of it, however, the two agreed that the game is getting boring. Because of this, they informed Tamaki that the game is over. Tamaki protested their decision and called them selfish but the twins admit that they are indeed selfish. The twins then decided to offend Tamaki by asking him if it’s true that he’s not the son of the board chairman’s legal wife. The two claimed that they feel sorry for Tamaki and told him that he probably doesn’t want this knowledge to spread as a rumour amongst the students. Moreover, it appears that the whereabouts of Tamaki’s mother is unknown. The twins also accused Tamaki of simply being lonely so they asked him not to selfishly tried to make them his acquintance. They pointed out that in comparison to Tamaki, who’s alone, being with each other is better. The twins admitted that they were always contradictory. They want people to recognise them but then they don’t want it.
They constantly seek people who can accept them but there was no one who’d accept them. They eventually believed that they won’t get hurt if they stay in their own world, one which was heavily locked. One day the twins did their usual trick, telling a girl that one of them is the other and then revealing that the real person is hiding behind the bush. The girl cried and ran away from the two but before Hikaru can rip out the girl’s letter, Tamaki yelled from a far, saying that the one who’s about to rip the letter is Hikaru. Hikaru was shocked to hear this but quickly asked Tamaki what is his reason for saying this. Tamaki simply told Hikaru that it’s his intuition. The twins were not impressed by this so Tamaki apologised and told them that it was kind of impossible because they look alike. Because of this, he thinks the two of them should be known as "The Hitachiin Brothers". Having said that, he hadn’t forgotten that the two are also two seperate individuals.
The twins claimed that the whole thing sounds contradictory. Tamaki does not see anything wrong with it because after all being contradictory is a part of their personality. It’s what people call "individuality". The twins became angry to hear this and told Tamaki that if they’re known as "The Hitachiin Brothers" then they’ll forever be remembered as a set. Kaoru also believed that no matter how much Tamaki tried, he could not possibly recognised them. He knew right from the start that there’s no one who could do the "Which one of us is Hikaru-kun game". The two then remembered of being surprised when the little girl from the flashback mistook Kaoru as Hikaru. Kaoru reflected how back then they probably wanted to cry. Tamaki told the twins that even if he couldn’t differentiate them, he believes that one day there’ll be someone who can. However, if they always stay in their own world, then they’ll never meet that person who can distinguish the two of them.
Because of this, he asked the twin if they’ll open the door of the Host Club together with him. He then told the two that the first meeting will be after the school’s opening ceremony in high school’s 3rd music room. A few days/months later, middle high school Haruhi came to see Ouran High, wondering if she can pass the examination. Behind Haruhi, Kyouya has also arrived at the school. Inside the school, Hunny found out that Mori has been invited by Tamaki to join the club. He also wondered if it’s okay for him to like cute things and cakes. In reply, Mori told Hunny that he should do what he feels. 1 month later, the twins were seen hesitating in front of the music room, telling each other that this is just to waste their time. Kaoru, however, remembered what the maid told them and realised that a person who could distinguish them is not in their world. Seeing Kaoru’s hesitation, Hikaru offered to open the door together. Kaoru narrates how the two then opened that door.