Keiko is Yusuke Urameshi's childhood friend and love interest.
Keiko is a childhood friend of Yusuke Urameshi and has always gone to the same school as he. Despite being a particularly bright young girl and Yusuke being the most notorious delinquent in the neighborhood, the two remained close friends and in their teen years, a romantic interest sprouted from their relationship.
Keiko Yukimura is a prominent protagonist created by Yoshihiro Togashi for the series Yu Yu Hakusho. She is one of the most important female protagonists in the series as the love interest to the main character.
Keiko develops primarily in 2 ways. The first is her relationship with Yusuke. It started as a friendship that sparked into romance when Keiko needed to kiss Yusuke in order to save his life. Later, this romance blossoms into real love and Yusuke proposes to her while still a teen but Keiko agreed to wait for him. Additionally, Keiko's actual physical growth was quite noticeable. She becomes taller and more shapely as she became a fine young woman.
Keiko is a young lady of average height and build. She has light skin and brown eyes. Her hair is also brown and initially is long, worn into 2 pigtails down to her back, but later in the story it is only shoulder length and not tied back. She is roughly 4 years older by the series' end than the beginning and grew accordingly, getting slightly taller and growing her hair longer once again. Her attire often consisted of her school uniform but when not in school she would usually wear a simple dress. During Keiko's development, Yusuke made a vulgar remark and stated that her rear had gotten nice since.
The two have grown up to be polar opposites, Keiko being the Straight-A student, and Yusuke, the juvenile delinquent. Despite this she is a loyal friend and goes to great lengths for his sake. From bringing him back to life after his death in the beginning of the series, to lending her support from the sidelines during his supernatural escapades, there really isn't anything Keiko wouldn’t do for Yusuke. Being his love interest, their mutual romance doesn't really come into fully bloom until the very end. Nevertheless, it's made quite clear that they care for one another deeply, throughout the series.
Yusuke Urameshi - Keiko's boyfriend who she is in love with.
Kazuma Kuwabara - Initially a friend of a friend but later on their relationship improves.
Botan - Botan became friendly towards Keiko after spending so much time around Yusuke.
Kurama - Helped rescue Keikofrom Hiei and continued to be a reliable friend afterwards.
Hiei - Initially her kidnapper but later a valuable friend.
Yukina - The younger sister of Hiei. Keiko befriended her when she met her at the Dark Tournament.
Koenma - Yusuke's guide and unofficial boss, but is also friendly towards Keiko.
Keiko Yukimura's childhood friend Yusuke Urameshi was killed in a car accident while saving a young boy. Unbeknownst to Keiko, Yusuke's spirit did leave his body but did not pass on. Instead, he was given a trial by Koenma, the son of King Yama of the spirit world. He would be allowed to return to his body and hence, to life if he completed the trial successfully, but he had only 3 days to do it.
In order for Yusuke to return, 1 obvious requirement was that his body remain intact. Yusuke appeared in Keiko's dream to comfort her. The next morning he was able to take possession of Kazuma Kuwabara and use the body to briefly to communicate with Keiko properly, that is after groping her. However that lewd gesture helped Keiko believe who Kuwabara really was which at that moment was Yusuke and did not need to be further convinced to believe what was happening. Yusuke said that he would be back very soon and told Keiko to tell his mother not to have his body cremated. Keiko was able to convince Yusuke's mother surprisingly easily. However, one last obstacle was to present itself.
Keiko had been taking care of Yusuke's body during the wait for his should to return, however an arsonist randomly set Yusuke's House ablaze. Keiko dashed into the burning house to Yusuke's body. She grabbed at and with difficulty, half dragged and half carried the body towards the entrance. The flames grew more intense though and things were looking hopeless. However Koenma offered a way out and Yusuke accepted without even listening to the conditions out of haste. Koenma parted the flames and Keiko managed to escape the blaze with the body. Koenma revealed that the condition was that a part of Keiko's body be taken which horrified Yusuke, but i was a false alarm and he only took some of Keiko's hair which is actually how Keiko's hair became shorter. In the anime, this happened slightly differently. Yusuke was given a golden egg that would be necessary for his revival, but instead, sacrificed it by having it thrown at the flames, dispersing it. The act of selflessness swayed Koenma to allow Yusuke to pass the trial.
The last condition was that Yusuke would need life energy transferred to him at midnight. The time frame was very narrow and he only was given one chance at this. Worse still, Keiko was not even aware of this condition. Yusuke had tried communicating with Kuwabara, but he was too skeptical and uncomfortable with the dream he had had with Yusuke trying to communicate with him. His mother was drunk and would not go to sleep which was necessary for the dream communication. That left Keiko alone as an option. Yusuke visited her in her dream and kissed her, hoping to convey the message. Keiko was not sure if that was Yusuke communicating with her or not and decided to tend to Yusuke drunk and sick mother. As a last effort, Botan, a reaper from the Spirit world who had become friendly with Yusuke possessed Yusuke's mother and through her, told Keiko that Yusuke needed her the most right now. Thinking that it was the mother speaking to her, Keiko ran up to Yusuke's room, saw Yusuke's glowing body and kissed him, just as midnight was about to pass. There was an instant of suspense, then Yusuke sat up in his bed, literally risen from the dead.
Shortly after Yusuke's revival,he took on the role of a Spirit Detective in the service of Koenma. By extension, Keiko was occasionally dragged into situations. When the fugitive demon Hiei had escaped into the human world, Yusuke as one of those that stood in his way. Hiei discovered through his subordinates that Keiko was an important person to Yusuke. He found Keiko and slashed her with his Conjuring lade which would eventually cause Keiko to turn into a Demon herself. Keiko was to be used as bait to lure Yusuke to him as well as a hostage so that Yusuke would surrender the necessary devices he needed to exact his plans of Human Extinction. Yusuke did indeed come, but he was not alone. Botan and Hiei's own ally Kurama interfered , the latter deeming the cause too extreme but wanting help in taking down Hiei, which Yusuke was more than willing to provide. With luck and the unexpected help of Kurama, Yusuke was able to narrowly defeat Hiei and with Botan's magic, release Keiko from Hiei's enchantment.
It was not long until Keiko was put in harms way again. Yusuke had entered the Demon realm with his allies and faced the Four Saint Beasts. Keiko along with Botan were chased by a legion of possessed humans including faculty at Keiko's school. They were possessed by Suzaku, the leader of the Saint Beasts all the way from the Demon World. Keiko used the chance to confess her jealousy of Botan's relationship with Yusuke, but was relieved when Botan said that they had no romantic feelings for each other. Eventually they were cornered and Botan tried to fight back but they wee grabbed. They were about to be killed when Yusuke who was observing the whole thing from the Demon world went Berserk by using his Life energy and defeated Suzaku all at once, nearly losing his life for using such power. The possession on the humans was broken, saving Keiko and Botan in the process.
Keiko and Botan discover Yusuke's secret trip to the Dark Tournament where he was competing against Demons. They travel there and find him. Keiko watched Yusuke's matches while looking after Pu, Yusuke's Spirit animal. It was also here than Keiko met Yukina, the sister of Hiei and ironically the girl Kuwabara had a crush on.
After Yusuke underwent the tremendously painful and tiring trial of absorbing Genkai's spirit orb in order to power him up enough to fight Toguro, he was left exhausted and slept for a very lengthy period of time. Keiko stayed with him, resting his head in her lap as they sat under a tree. They were approached by a group of demons with non innocent intentions but they were rapidly disposed of when Chu, Rinku and the other member of team Chu arrived. They had lost to Yusuke's team before but had gained his respect. They said they would leave Yusuke and Keiko to their ""business" automatically assuming that they were being intimate with one another.
When Yusuke finally engaged Toguro in combat, he was beaten down viciously. Keiko began to hallucinate presumably due to the strain of seeing Yusuke go through the punishment. However, Yusuke eventually won the battle and came over to the unresponsive Keiko and woke her up by slapping her. Once awake, Keiko slapped Yusuke back.
Keiko joined Yusuke and the rest in their group meetings and she was no longer isolated or kept in the dark. Keiko was with Pu when it transformed into a Giant Bird and flew off to Yusuke when he had revived from his apparent death at the hands of Shinobu Sensui.
After Yusuke returned from the Demon World, he told Keiko that he would have to go back. Keiko became angry at him thinking that he might not come back this time. She told him that she would go to an All Girls School for High School then said she was through with him. Later that evening however, Yusuke came to Keiko again and proposed to her for marriage. Keiko did not even initially realize that he was serious since he had done this in the past without being serious. He assured Keiko that he was serious now. Yusuke said that he would be back in 3 years and needed Keiko to wait for him. Despite what she had previously said, Keiko said that she would try and wait for him.
Keiko is next seen at age 17 in high school. She was preparing for college now, intent on becoming a teacher. Keiko, Botan, Kuwabara and Yukina convened at Genkai's house as she lay dying. Her final will was read out (this did not happen in the anime). After meeting with Genkai, the group headed for the beach. There, Keiko had a meltdown and painfully said that she was giving up on Yusuke who she believed had abandoned her forever to pursue his desire to continue fighting. It was that moment that none other than Yusuke was spotted on the beach as well. Kuwabara told Keiko that Yusuke had called her his "Goddess" which was a term he used for Keiko alone. This again rekindled Keiko's love for Yusuke and she ran to him.
In the anime she actually kisses him then they proceed to play in the water.
Yu Yu Hakusho the Movie: Poltergeist Report (Movie)
Yu Yu Hakusho: Spirit Detective as non-playable (Game)