"Being from a wealthy family may sound good, but that's why Tsukasa could never make friends. The arrogance was his way of protecting himself against the loneliness, before he met up with Sojiro and Akira. Of course, I can't say I brought him up in any normal way."
She was the elder sister of Tsukasa by four years. Their parents were constantly busy working abroad, leaving their children by themselves in Japan. Tsubaki credited herself with "raising" Tsukasa due to them being alone so often. She admitted that she did not do it in "any normal way," referring to the times she hit or kicked him to keep him in line.
In high school, Tsubaki represented Eitoku Academy at Teen of Japan. The contest was particularly fierce that year. Tsubaki ended up winning it since she was the only one able to make an okonomiyaki in the final round. She had learned to make it years previously to make Tsukasa happy. Tsubaki also modelled in Paris during this time.
Tsubaki fell in love with an ordinary boy during her third year of high school. Her mother, however, arranged a marriage with a hotel magnate's son since she wanted to expand her business. Tsubaki fought against it, running away several times but the arrangement proceeded. Her future husband later told her "I'll wait for you to turn to me, whether it takes 10 or 20 years. Then if the whole world becomes your foe, I will be your only ally." His words resonated with Tsubaki, whom later grew to love him. They were married while Tsubaki was still in college. Her wedding gown was ordered from Chanel. She moved with him to Beverly Hills.
"I think I can entrust Tsukasa to someone like you. He acts tough, but he's not so bad. If you can, try to understand him."
After being away for three years, Tsubaki decided to go home for a visit while her husband was away on business. She had to walk home from the airport and ran into a girl, Tsukushi Makino, on the way. She was being bothered by a guy, so Tsubaki scratched his car to make him leave. Tsubaki then insisted that she come home with her. Tsukushi, however, disappeared while Tsubaki was speaking to Tsukasa. Later, Tsubaki found Tsukasa holding Tsukushi's arm. She proceeded to beat him up. Over dinner, a drunk Tsukushi admitted to knowing Tsukasa. Tsubaki then had Tsukasa carry her to a room. Once Tsukushi woke up, she told her "I wish you wouldn't give up on Tsukasa." The next morning, she asked Tsukasa several questions. He became angry when she mentioned Rui Hanazawa, leading her to guess that they had fought.
That night, she overheard Tsukasa arguing with Sojiro Nishikado and Akira Mimasaka. On their way out, Tsubaki accosted Kazuya Aoike and forced him to tell her everything. The next day, she rushed to Eitoku. She stopped Tsukasa from blackmailing the principal into expelling Rui and Tsukushi. When everyone began bickering, Tsubaki told them to "settle" the problem through sports. They subsequently decided to play a game of basketball, which Tsubaki refereed. The game ended abruptly when Tsukasa declared "I quit" and left. Afterwards, everyone, except Tsukasa, went to celebrate at the Domyojis'. A drunk Tsubaki learned that Tsukushi and Rui had not slept together and had them forced into a guest room. When Tsukasa arrived home, his sister explained it to him and he took it calmly.
The following day, Tsubaki told Tsukasa that their father had called to ask about him going to school in New York again. Tsukasa interrupted her to say he "made up [his] mind" to go. Tsubaki was taken aback by his change-of-heart since he had always been against it. Tsukasa stood by his decision, revealing that he had decided to do it before the basketball game. Tsubaki realized he was serious and agreed to go with him. A couple days later, she and Tsukasa were seen off by the F4. Once the plane took off, he suddenly declared he wanted off and started making a scene. Tsubaki had the attendants help her restrain him. In New York, Tsukasa complained about everything which annoyed his sister, who promptly kicked him. She later left Tsukasa on his own to do some shopping by herself.
Teen of Japan
Tsukushi: "An okonomiyaki determined the winner...?"
Tsubaki: "Yes, there's no telling what will happen in this contest. You've got to prepare yourself for anything. Tsukushi, will you give yourself up to me for the next two weeks? Do that and I'll turn you into an unsurpassable young woman."
Tsukasa suddenly disappeared from New York, causing their parents to worry he had been kidnapped. Their father asked Tsubaki to keep an eye on Tsukasa. When she returned to Japan, Tsubaki angrily confronted Tsukasa for not telling her he was leaving. Tsukushi arrived at the house shortly later to ask Tsukasa for a one million yen loan. Tsukasa consented as long as she agreed to enter Teen of Japan. The next day, Tsubaki asked Tsukushi to come over. She asked Tsukushi if she intended to win the contest. Tsukushi answered "Yes, I do." Tsubaki described the year she won Teen of Japan in great detail. She then promised to "turn [Tsukushi] into an unsurpassable young woman." Later, Tsubaki warned her brother not to sneak into Tsukushi's room while she was staying with them.
The next day or so, a servant reported to Tsubaki that Tsukushi was missing. She had the servants search for her. Tsubaki then went into Tsukasa's room, where she found the two innocently sleeping together. On Christmas Eve, she watched the contest. She kept a running commentary throughout the first round, saying at the end "My heart can't take much more of this." Before the second round, Tsubaki expressed some apprehension on Tsukushi's ability to know "what the upper class is supposed to know." She seemed correct by the topic the judge spoke of. Thankfully, Tsukushi managed to impress her and Tsubaki was very proud. Tsukushi passed to the final round and ultimately placed second. Tsubaki congratulated her on winning the special award.
Opposing her mother
"She's very hard to please--especially when it comes to women. If she finds out that Tsukasa has invited a girl. Well... Tsukasa is this family's heir, you see. There's the future to consider..."
On January 31, Tsubaki flew in to celebrate Tsukasa's birthday. Akira asked her to lend Tsukushi a dress. Tsubaki settled on a dress she made during middle school. A confused Tsukushi asked "Why do I have to dress so perfectly?" The F4 replied "Tsukasa's mother is really scary!" Tsubaki told her that her mother was "very hard to please." During the party, Tsukushi accidentally caused a scene. Tsubaki tried to defend her but her mother told her to "stay out of this." Rui ended up lying to Kaede about Tsukushi's background, ending in a disaster. Tsubaki gave Tsukasa some car keys after their slapped him for saying he loved Tsukushi. The couple then made their escape. Later that night, Tsubaki spoke to her mother's secretary Nishida about their plans for Tsukasa. He replied "I'm not at liberty to say."
The following morning, Tsubaki was surprised her mother had not returned to New York yet. She asked her about her plans for Tsukushi and Tsukasa, mentioning what Kaede did to her in the past. Kaede told her "Such things are meaningless in the great scheme of life." Tsubaki later cried, saying "'Meaning' is something you will never understand." Following Tsukasa's broken engagement, Sojiro and Akira told Tsubaki that Tsukushi "declared war" on Kaede. Tsubaki later received a call from a friend of Tsukushi's. He called her a "clown," apparently thinking she was Tsukasa. Tsubaki then went to his apartment to pick up Tsukushi, who remained asleep the entire time. Once Tsukushi woke up, she tried to run away but Tsubaki stopped her. She then invited her to live there, saying "Let's get her to realize the good in you."
"You know Tsukushi... You may be annoyed to hear me say this, but I don't want Tsukasa to have to go through what I did. Besides, I really like you! I definitely want my mother to see how wonderful you are. So please think it over. About living with us. I think it's a good chance for you to settle things with Tsukasa."
—Tsubaki invites Tsukushi to live with her and Tsukasa[src]
Tsubaki told Tsukushi about her arranged marriage. She admitted that she was happy now, though a part of her wondered whether she should have tried harder. Tsubaki then asked her to consider living there since it would be a good opportunity to "settle things with Tsukasa." The next morning, when Tsukasa returned home, Tsubaki tried to make him leave. It was too late though since Tsukushi appeared before them saying "I will work as long as I am here." Tsubaki was against the idea, but Tama, the family's head maid, agreed to train her. Eventually, she went along with it when Tsukushi confirmed that working as a maid there was what she wanted to do. In the morning, Tsubaki heard Tsukushi screaming though it ended up being a misunderstanding. She later spoke to Tama wondering "if those two are all right."
That night, Tsubaki dressed up for a party for some guests from overseas. Tsukushi ran up to her on her way out. Tsubaki was unable to talk since she was running late. She asked Tsukushi to have dinner with Tsukasa before leaving. A few days later, Tsubaki was overjoyed to learn that Tsukushi and Tsukasa were dating. She was already thinking about a wedding when Tsukushi informed her "It's no good after all." Tsubaki then exclaimed "But it's only been four days!" Almost right after, she flew back to Los Angeles. While away, Tsubaki picked out gifts for Tsukushi. Upon returning, she learned that Tsukushi had left. Tsubaki said to Tama "I guess my mother is far more cunning than I imagined." She then asked about Tsukasa and guessed correctly from Tama's statement that he had "gone back to his wild ways."
Reuniting with her cousin
"Tsukasa, when it comes to Tsukushi, you've been acting like a spoiled little rich boy. You're like a kid who's crying because he can't get the toy he wants. At every turn you rebel and say you're going to leave home and live alone. If you keep attacking from the outer moat, you'll never reach the chatelain. You have to face the chatelain and slay him, or the castle will never fall."
Sometime later, Tsukasa asked Tsubaki about their cousin, Kiyonaga Narumiya, who was hanging around Tsukushi. She speculated that he could be the "right choice" for Tsukushi. Tsubaki went on to say that Tsukasa had been acting like a "spoiled little rich boy" and that he needed to "face the chatelain." He did not understand her analogy. The next day, Tsukasa convinced Tama to take him to meet Kiyonaga. Tsubaki told her that she was being "much too soft on Tsukasa." They took the train, at Tsukasa's insistence, to Kiyonaga's apartment. Tsubaki and Tama were both glad to see him doing well. Tsukasa suddenly started pulling his cheeks, claiming he was wearing a mask. Tsubaki yelled at him to stop until Akira pulled him away. Akira then said that Kiyonaga was not the same person around Tsukushi.
The next day, Tsubaki was shopping when she happened to meet Tsukushi. She was happy to see her, but became worried that Tsukushi had not been eating well. First, Tsubaki took her to buy a dress and then to a restaurant. They discussed the "fake Kiyonaga" and Tsubaki asked if she was going to date him. Tsukushi apologized, saying "I failed after all." Tsubaki responded "I will be satisfied as long as you are happy." After saying goodbye, Tsubaki saw Tsukushi chasing after her car and stopped. She confessed that she loved Tsukasa but did not want to be forced apart again. Later, Tsubaki asked Tama if she knew about Tsukushi's feelings. They both decided not to tell Tsukasa. Tsubaki could not help calling him a "fool" when he walked in. He said "I'm about to do the most foolish thing in my life," before leaving.
Tsukushi and Tsukasa dating
Tsubaki arrived back in Japan several days later. She was angry about the presence of her family's secret police and demanded to see Tama, whom revealed that they were there to prevent Tsukasa from leaving. Tsubaki then stormed around the house looking for Tsukasa, but he was not there. When Tsukasa came home that night, Tsubaki burst into his room and found him with Tsukushi. She closed the door for a moment but returned to punch Tsukasa, believing he was forcing himself on Tsukushi. Once she had calmed down, the couple revealed that they were dating. She was overjoyed and hugged Tsukushi. However, she realized that she had not "barged in at the wrong time." Tsubaki told her brother to be "more considerate" of Tsukushi. He agreed to wait for her and Tsubaki left to find some wine to celebrate.
Tsubaki was one of the few women Tsukasa considered "beautiful." Tsukushi had a similar sentiment, calling her "just as beautiful as Shizuka." Tsubaki had in fact, like Shizuka, worked as a model during high school and college. She had long, dark brown hair which she usually wore down. She had a large collection of clothes, having a particular love for name-brand fashions.
Personality and traits
She was a nice, considerate person with a strong sense of justice. Her personality was similar to Tsukushi's, which Akira pointed out to Tsukasa. Tsubaki was well-known for her hot temper and her willingness to throw a punch, mostly at Tsukasa. Her age made her mature and perceptive in matters of emotions. Nevertheless, she was occasionally prone to misunderstanding situations and jumping-to-conclusions, especially if Tsukasa was involved. Tsubaki supported Tsukasa and Tsukushi being together and had faith that her mother would eventually accept them. She deeply cared for Tsukushi and treated her like a sister.
One reason Tsubaki supported Tsukasa's and Tsukushi's relationship was her own situation with her high school boyfriend. Though she loved her husband, she sometimes wondered why she did not try harder to be with her first love. However, part of her also realized that she would not be able to leave her privileged life. Tsubaki wished that Tsukasa would not have to go through a similar situation to hers.
Her given name, Tsubaki (椿,Tsubaki) means "camellia," a flower particularly famous in East Asia. In Hiragana, Tsubaki is written as つばき. She and her brother also share the first syllable of their name. Tsubaki's last name is composed of three kanji, 道明寺,道明寺. The first, 道,道 has several different meanings, including "street," "journey," "course," and "teachings".明,明 can mean "bright, light" and 寺,寺 usually means "temple". Her last name is written as どうみょうじ,どうみょうじ in Hiragana.
She is mentioned several times in the film, Hana Yori Dango (1995). Tsubaki moved to Beverly Hills with her husband the previous year. Tsukasa misses her but will not admit it. Sojiro and Akira tease him about her similarities to Tsukushi, which he denies. Tsukasa later exclaims "Onee-chan!" after Tsukushi kicks him in the chest, apparently now seeing the similarity.
In Hana Yori Dango: The Musical (2016), Tsubaki is mentioned by Sojiro and Akira after Tsukushi punches Tsukasa. They later tease Tsukasa by comparing Tsukushi to Tsubaki.
Tsubaki is mentioned several times in the musical, Hana Yori Dango (2019). She is first mentioned by Akira and Sojiro, comparing Tsukushi to her. Tsukasa mentions her thereafter and always with a tone of affection, such as when he informs Tsukushi about Tsubaki winning Teen of Japan.