Hanabishi Kaoru is the male lead in the ani-manga romance series, Ai Yori Aoshi. The subject of a crush by many of his female friends, he is secretly betrothed to the woman they believe to be merely his landlady, Sakuruba Aoi. Kaoru unwittingly placed this childhood engagement with his friend Aoi in jeopardy when he left the Hanabishis and their ways behind him to start a new life on his own.
Kaoru's parents were never allowed to get married. What is known is that his mother was not approved of by his paternal grandfather, a strict and harsh ultra-traditionalist given to excesses of discipline. His father died in an accident when Kaoru was very young, and his mother was compelled to let his grandfather adopt him when he was five, dying herself two years later. Kaoru stubbornly held onto his mother's memory against abuse both verbal and physical. Though forcing him to yield up mementos, Kaoru again kept to the memory of his mother. Years later, Aoi was shocked to see the scars on his back from where his grandfather had whipped him. While Kaoru was certainly not fond of such physical abuse, it was less this than the determination of his grandfather to effectively erase the memories of Kaoru's mother that finally drove him away. Gathering what money he could and keeping it in separate accounts unknown to his grandfather, Kaoru bolted when he came of legal age and began living in a small apartment while attending college.
Besides Aoi, young Kaoru had a childhood friendship with the younger Miyuki Mayu, whose own loneliness he helped cheer, causing her to fixate on him with a deep crush. In college, American expatriate and fellow photography club member Tina Foster fell deeply in love with him. Though he did not return her love in the same way, he treasured their friendship and came to enjoy her lack of inhibitions in expressing exactly how she felt. When she left to go home to America, he did indeed miss her. Minazuki Taeko was another member of his photography club, also sporting a crush on him. While the reality of this encounter is impossible to determine, Kaoru is depicted as having once met someone who claimed to be Santa Claus - but who looked exactly like Aoi, and who promised him his lonely times would end soon. This was the Christmas before he was first reunited with Aoi.
The two encountered each other once again when he found Aoi, who he did not recognize (nor she him). Aoi was looking for someone who turned out to be him. Her beauty and charm and the good memories from childhood had Kaoru rapidly falling in love with Aoi, but he realized her absence would worry her family, so he sent her home - this after a night she helped warm his body with her own - although innocently. When Aoi refused to leave his side, even at the urging of her guardian Kagurazaki Miyabi, his resolve began to grow to marry her despite wedding plans past and present. Moving into and setting up a new household under conditions laid down by the Sakurubas, Kaoru and Aoi resolved to rise above every obstacle laid against them so that they could be together.
Soon after, Kaoru was reunited with Tina, who had returned to Japan, and in order to keep the relationship a secret as they agreed to Aoi's family, Tina, Taeko and later on Taeko's younger cousin Minazuki Chika all moved into rooms at the cottage that Kaoru pretended to rent from Aoi which Miyabi managed. Miyabi for her part made sure to emphasize how much the Sakurubas wished him to return to the Hanabishis. Partly from this and partly in order to move on with his life and deal with his rage over his grandfather's abuse, Kaoru did indeed journey back to his grandfather's home, fully prepared to confront the old man for his cowardly bullying of a small boy. His rage dissipated, though, when he found that his grandfather was now a wasted man, likely dying and barely able to recognize him. He now felt nothing for his grandfather, not even hate, and made his choice to leave the Hanabishis forever, a fact he made fully clear to Miyabi. When she in turn informed the Sakurubas that his choice was now irrevocable, it set events in motion that brought the series to a conclusion. Not long after his visit, a news report told of the old man's death.
Life had reached a good peak in the cottage; Most were getting along, Miyabi had taken to Uzume, a pet ferret bought by Tina, while Tina and Mayu seemed to get along by never getting along, with Mayu even becoming upset when Tina announced she was leaving Japan. Tina confessed her love to Kaoru, while he in turn privately revealed his and Aoi's secrets, facts which saddened Tina but also gave her hope for storybook romances coming true. For a time, it seemed the biggest incident of any note would be Kaoru walking in on Chika and her friends horsing around while bathing. For the record, the girls, once mortally embarrassed, later started fantasizing about Kaoru as a boyfriend.
But ominous signs began to show. From his dazed stupor, Grandfather Hanabishi looked up and called another young man Kaoru. This turned out to be the half-brother of the main Kaoru, with the same name and with bitterness instilled in him by a mother who was also excluded from being with the two Kaorus' father. Determined to take everything he felt his half-brother had taken from him, the once-excluded heir joined with Aoi's father for a scheme to end the relationship.
When Aoi was told her father had collapsed, she rushed to meet him at a house that turned out to be a trap set by her father and the other Kaoru Hanabishi. Miyabi obeyed her orders in helping set the trap, but then resigned her position and aided the main Kaoru in trying to recover Aoi. The other Kaoru appealed to Aoi's sense of family obligation, and demonstrated that her Kaoru was not and never would be ready for the life they were destined to lead. Unknown to most, the other Kaoru had seen their Grandfather's will, giving the entire Hanabishi Zaibatsu to the man who married Sakuruba Aoi. With the aid of his friends, the main Kaoru raided the compound as Aoi's resolve finally weakened under pressure from both the other Kaoru and her father. The pair sadly renounced their family names, with main Kaoru surrendering his claims to his half-brother, bringing the two some measure of peace. The two married and lived a simple existence, hard sometimes but worth it to be openly together. It is worth noting that by the end of the series, the scars on Kaoru's back from his grandfather's whippings had all but vanished, indicating that Aoi's love had healed him.
The anime's first season finale went similarly to the manga ending described above, but did not end (onscreen) in marriage, and did not involve the other Kaoru. Once married, the couple assumed the family name Honjou, the surname of Kaoru's mother.