Sentaro Daimonji

Sentaro Daimonji is the heir to the Daimonji School of the Martial Arts Tea Ceremony, of which his grandmother is the current head.

Sentaro means "boiling great son," which may be a reference to the fact that he is about to inherit his family's legacy. Daimonji is "(Dai) faithful service to those older + (mon) problem (or some monkey reference) + (ji) pity".

Overview
The heir to the House of Daimonji and fiancé of Satsuki Mikaoji, Sentaro is a user of the martial arts style of tea ceremony. As sole heir to the school, he is expected to marry, but wishes to choose his bride rather than have one selected for him.

Martial Arts Tea Ceremony
After finally meeting his fiancé, Satsuki Miyakoji, Sentaro can't bring himself to like her and ends up fleeing his home on his horse. Whilst riding, he loses consciousness, but is stopped single-handedly by Ranma, who'd been trying to escape from Shampoo earlier. When Sentaro comes to he is met by Ranma (who's in his female form due to a downpour earlier) and offers her some tea. Ranma accepts the offering, but soon regrets it as Sentaro laced it with paralysis potion and puts her on the back of his horse before riding off with her back home.

As he heads home, Sentaro passes Akane, who notices Ranma on the back of Sentaro's horse and tries to stop him. However, Sentaro fends off Akane's attack and pins the hood of her coat to a nearby lamppost with a Tea Ceremony spoon. Some time after returning, Sentaro has Ranma dressed into a wedding Kimono.

Once Ranma awakens, Sentaro tries to explain himself, but Ranma doesn't want to her any of it and attempts to leave. Fortunately for Sentaro, his Grandmother ends up making Ranma accept to participate in a match of Martial Arts Tea Ceremony to see if she's worthy of being Sentaro's bride. Sentaro then quickly plans on starting Ranma's training the next morning, but is horrified to learn of Ranma's Jusenkyo curse. As Sentaro weeps at his misfortune, Ranma suggests he just gives up and agrees to marry this "Miss Satsuki" he's engaged to, but Sentaro refuses to give up.

Just then Akane arrives to retrieve Ranma, but ends up being wrapped up in by Sentaro as well as a possible replacement for Ranma. Unfortunately, despite being taught by Kasumi how to perform Tea Ceremony, Akane lacks the patience to do so, making Sentaro decide to go back to having Ranma fight in the match. Sentaro begins is training of Ranma, who initially struggles to match Sentaro's ability to glide seamlessly across the floor. Luckily, after Ranma observes how Sentaro's Grandmother is able to walk on the ceiling she soon becomes a master of Martial Arts Tea Ceremony like Sentaro.

After a long night of practice, Sentaro takes Akane and Ranma to where the fight against Miss Satsuki will take place. As Sentaro describes Miss Satsuki to the pair, she initially seems like the perfect wife, until Sentaro show them Miss Satsuki in person, who turns out to be a monkey! Now knowing that Miss Satsuki is a monkey, Ranma immediately goes against the idea of fight, taking pleading from Sentaro along with an unprovoked attack from Miss Satsuki before she ends up participating.

Sentaro doesn't watch the fight for long, however, as he takes Akane outside with him and declares that he will mortally wound Ranma and Miss Satsuki so that he can become engaged to her instead. Once the fight overflows to outside of the arena, Sentaro waits until Ranma's about to defeat Miss Satsuki to interrupt the fight and attempt to enact his plan. However, just before he is about to stab the paralysed Ranma, Akane kicks him across his estate. As he flies, Sentaro ends up crashing into the real Miss Satsuki, who'd sent her monkey, Sanae, in her place as she was too shy to initially go herself.

Having finally met the real Miss Satsuki, Sentaro instantly falls in love with her and the pair are soon married and off on their honeymoon. Sentaro also makes sure to send Ranma a latter along with a picture of him with Miss Satsuki. Despite the letter saying they'd probably never meet again, as Ranma reads the letter, Sentaro and Satsuki appear at the Tendo Dojo as they'd gotten lost whilst riding Sentaro's horse...

Martial Mayhem
One rainy day, Sentaro is riding his horse, Tsukikage, when he loses conscious. Sentaro ends up riding into a busy shopping plaza, where he's stopped by Ranma, but not before Tsukikage manages to hit Ranma with one of his hooves. When Ranma comes round, she goes to see if Sentaro is alright and after slapping him multiple times, Sentaro comes round too. As way of a thank you, Sentaro prepares Ranma some tea, but this turns to be laced with paralysis powder which renders Ranma unconscious again and allows Sentaro to take her away with him.

As Sentaro takes Ranma with him, they pass Akane. When Akane sees Ranma on the back of Tsukikage she attacks Sentaro with her umbrella, but he quickly stops it and sicks a Tea Ceremony spoon into the hood of her coat, which also lodges into the lamppost behind Akane. When he returns to his estate, Sentaro has Ranma dressed in a wedding Kimono and waits for her to awake. Once she does, Sentaro apologises for his rudeness and attempts to explain himself, but Ranma isn't willing to listen and begins to kick Sentaro.

Through Sentaro's Grandmother, Ranma learns about Sentaro being made to marry so he can become the master of the Daimonji school of Martial Arts Tea Ceremony. Sentaro also tells Ranma about how he wishes to choose his own bride, he then reveals that he intends for Ranma to defeat his Grandmother so that he can cancel the wedding meeting that has been arranged for him. After being provoked by his Grandmother, Ranma agrees to fight for Sentaro, but doesn't realise that if she wins she'll have to marry Sentaro before it's too late.

With the challenge set, Sentaro makes preparations to teach her about Martial Arts Tea Ceremony, however, before the training begins, Ranma reveals his curse to Sentaro. After checking that Ranma is indeed male, Sentaro asks why he accepted the challenge, but he continues weeping and doesn't listen to what Ranma tries to say. At that moment, Akane appears looking for Ranma and the pair meet her. When Sentaro notices Akane has his Tea Spoon he hugs her with gratitude, but ends up getting hit by both Ranma and Akane for it.

Knowing Ranma's condition, Sentaro offers Akane the chance to participate in the match instead of Ranma. This idea doesn't last long, however, as Akane hasn't anywhere near the amount of patience required for Tea Ceremony. Ranma then offers to perform in the match after all and once Sentaro's has some internal contemplation he decides to agree out of sheer necessity. Despite initially struggling with the training, Ranma soon gets the hang of it and after a long night of training, Sentaro tells her she's ready for the match.

Later that day, Sentaro watches the match between his Grandmother and Ranma with Akane. After Ranma struggles trying to defeat Sentaro's Grandmother, Sentaro offers Ranma some tea, but soon regrets it as once again the tea is laced with paralysis powder. Sentaro then tells Ranma he has no need for him as he's decided to take Akane as his bride, he then proceeds to kidnap Akane in an attempt for them to elope. Unfortunately for Sentaro this plan doesn't go very smoothly as Akane kicks Sentaro into the air shortly after he kidnaps her, as well as severely injuring Tsukikage. Sentaro then comes crashing into his estate and destroys a good portion of it, brining an end to the Tea Ceremony match.

On a rainy evening, the most skilled disciples of the Daimonji school gather to prepare for the day of Tea Ceremony. During their meeting, Sentaro's grandmother reveals that she plans to take a stand on that day, which the other disciples, including Sentaro, view as a crisis for the school. Deeply concerned with the situation, Sentaro goes to Ranma for help and, after a few failed attempts to get to Akane, reveals that ever since his grandmother made her decision bad omens have been happening all around him. He continues by noting that nobody, not even him, has ever seen his grandmother stand. Now begging for help, Akane agrees to help, as does Ranma who wants to finish off his fight with Sentaro's grandmother.

When the trio arrive at the Daimonji school that evening, Sentaro leaves Akane and Ranma in a room while he goes off to meet several school elders. The elders ask Sentaro is he brought the girl, to which Sentaro says he has, but another came with them. Sentaro then learns from the elders that only one other case of the grandmaster of Tea Ceremony taking a stand has ever occurred, and during that event a maiden was offered and the situation was averted.

Sentaro is then asked what the name of the maiden is, to which Sentaro says it's Ranma (although Akane was the originally intended maiden). Some time later, Ranma and Akane are taken to a cleansing ceremony, where the pair are knocked out with Ranma being carried away to another room. When Akane comes round she demands Sentaro explain what's going on and in a panic Sentaro reveals about Ranma being sacrificed to his grandmother. Akane then plans to take Ranma home, but Sentaro tells her that time is short and she won't be able to defeat the guards in time. Sentaro then offers to train Akane, but this turns out to be a shameful attempt to get Akane to admit her feelings for him, so Akane ends up throwing Sentaro against a wall for waisting her time. But before Akane gets to fight the guards, Sentaro offers her the use of his horse as way of apology.

Through a combination of Sentaro attempting to elope with Akane and Tsukikage going wildly off course, the pair get past all of the guards and reach the chamber where Sentaro's grandmother is situated. While Akane sees what Sentaro's grandmother meant by "taking a stand", Sentaro tries to clam down Tsukikage. Unfortunately, Tsukikage ends up destroying the chamber and Sentaro's grandmother puts him through an intensive training session as punishment (during this time Akane and Ranma decide to return home).

OVA
Sentaro along with Satsuki were two of the many guests invited to the Tendo Family Christmas Party, where he brought a gift especially for Akane. Unfortunately, his gift was removed by his Grandmother who was determined to come too, even if her grandson didn't want her to.

Non-canon Appearances
Sentaro is mentioned in the alternative version of Lambada Ranma, which features characters from later in the anime's run. He also has his own song in the Fighting Songs Karuta album, Hanashi wo Kiite Okureyasu.