Residents of Yuragi-sou
Kogarashi Fuyuzora
Yuuna and Kogarashi.
Kogarashi is the new resident of the Yuragi-sou and Yuuna's roommate in Room 4. Since he is the first person that wasn't afraid of her despite sharing the same room and after rescuing her from a monk, Yuuna becomes very attached to him. Many of Yuuna's actions cause Kogarashi trouble with those around him, though this never appears to bother him because of how he was used to such misfortunes in the past by being possessed by many ghosts.
To help Yuuna pass on, the two have done a myriad of activities (dates mostly) together.
As the story progresses, Yuuna is shown to grow more and more attached to Kogarashi, due to the kindness and understanding he constantly shows her throughout their constant interactions. One instance is during the School Trip when Kogarashi offers to dance with Yuuna around the bonfire despite the potential rumors that would spread about him. Another time was when Kogarashi ends up working late and gets sick to get her a birthday present. This made her develop romantic feelings for him, which confused her because she wondered if she was even allowed to have such feelings because she's a ghost and Kogarashi is human.
During the Cultural Festival, she tells Chisaki how she doesn't mind if Kogarashi were to fall in love with someone else and that she give them her blessings. However, during the School Play, Chisaki confronts Yuuna that she should be herself and that they will find a solution. This made Yuuna's feelings for Kogarashi blossom even further, making her ponder if it's alright for a ghost to truly fall in love.
When Chisaki visits Yuuna at the Yuragi Inn and consults with Yuuna again about her feelings, Yuuna once again becomes unsure of her feelings until Chisaki asked again if Yuuna was ok with Kogarashi ending up with someone else. Yuuna realizes how she doesn't like the idea, giving her revelation that she really is in love with Kogarashi.
Yuuna & Kogarashi Date
After she admits to herself that she is in love with him, she later admits it to Chisaki and Hibari who also are in love with him. Since, she has tried various ways to get even closer to Kogarashi. An example is how she becomes more forward in the dates they go together to help pass her on.
On Valentines Day, at the end of Chapter 69, when she finally was able to give her chocolates to Kogarashi and have dinner with him along with everyone else, she unconsciously confesses her love to him, much to the girls' shock. Yuuna realizes and couldn't sleep while remembering the event. She was extremely happy when Kogarashi gave her a handmade blanket for White Day.
Her love for Kogarashi is so strong that in their final battle with Byakuei's, she's able to possess Kogarashi and grants him an immeasurable amount of spiritual power to defeat Byakuei and his ambitions. Her love also is the reason that she doesn't decide to unlock her lost memories and discover her lingering regret, despite having the power to accomplish it, because she wants to stay with Kogarashi a bit longer, much to his delight.
When hints of the seal to her memories begin to break, she broke this Kogarashi. During this same conversation, after many supports from her friends and the scared realization that she might disappear after recovering her memories, she officially confesses that she is in love with him.
At the end of the series, Yuuna feelings were reciprocated and the two work together at the Yuragi Inn.
A running gag is how Yuuna develops a bad sleeping habit where she constantly crawls to Kogarashi's futon, wakes up in a lecherous position with him, and sends him flying with her poltergeist out of embarrassment.
Chitose Nakai
Nakai was the first person Yuuna meets after awakening as a ghost in room 4 in the Yuragi-sou. Being both supernatural entities they were able to become close friends. Nakai is the one who gave Yuuna's name and establishes the day Yuuna awakened as a ghost for the first time as also her birthday.
Ameno Sagiri
Yuuna shares a close friendship with Sagiri as fellow Yuragi Inmates. Yuuna became attached to Sagiri when she said how cute Yuuna was and wasn't afraid of her. Sagiri was originally distance towards Yuuna due to how over-friendly she was along with Nonko and Nakai. It was until after being saved by them in one of her Chuuma Missions did she start opening herself towards them. When Sagiri realizes she's in love with Kogarashi, she tells Yuuna, making the two love rivals.
Ameno Hibari
When Yuuna was unsure of her feelings for Kogarashi, she claims she didn't mind the idea of Hibari going out with Kogarashi. After Yuuna realizes she is in love with Kogarashi, she also realizes how she actually didn't like the thought of Kogarashi being with Hibari or any other girl. When Yuuna confesses her feelings about Kogarashi to Hibari, along with Chisaki, they became love rivals and friends.
Yukemuri High
Miyazaki Chisaki
A high-school student who is also Kogarashi's classmate, as well as Yuuna's few human friends outside the Yuragi Inn. Yuuna finds Chisaki cute and wanted to check out her panties so she can create them for herself with her spiritual clothes. Chisaki wanted to know more about Yuuna after becoming aware of her existence after she helped her from a spiritual phenomenon involving Koyuzu. The two would often communicate by writing a notepad. This changes when Koyuzu creates fakes bodies for Yuuna to posses and changes again when Chisaki finally gains spiritual awareness abilities.
They are close enough that Yuuna would ask Chisaki advice regarding Kogarashi. It was through these conversations that both Yuuna and Chisaki began to realize their mutual feelings for Kogarashi. When they both, along with Hibari, confronted their feelings about the matter, they all became happy to share these feelings and officially announcing each other as love rivals.
Yuuna possessing Chisaki.
After Chisaki gained spiritual powers and ability to see ghosts, Yuuna starts spending most of time with her, following her wherever she goes, most likely in order to protect her from other ghosts as Chisaki is now more vulnerable to possession. This strengthens their friendship even more to point that Chisaki has no problem allowing Yuuna herself to possess her, if needed.
Others
Hiougi Karura
The Tengu who controls the Yokai in Kyoto. They started as adversaries when Karura invades the Yuragi-Inn and kidnaps Kogarashi. After learning that Kogarashi was going to marry Karura through an enslavement contract, Yuuna, along Sagiri, Hibari, and Yaya, immediately set out to stop wedding. After Kogarashi, Yuuna also discovered that Hiougi Karura was actually in love with Kogarashi. When Yuuna was able to free Kogarashi from the enslavement spell, the Tengu starts wondering Yuuna's true identity. Afterwards, when Karura apologizes to everyone, Yuuna now competes with her for Kogarashi's affection under more friendlier conditions.
In spite of their original encounter, Karura originally doesn't see Yuuna as a serious threat for Kogarashi's affections due to how preserve she is. However, when competing with Yuuna and Chisaki in a water gun fight game where a Love Potion was the reward, Karura now sees Yuuna (and Chisaki) as official "love enemies" for Kogarashi after seeing their strong determination.
When Yuuna was under the suspicion that she was Garandou, Karura was the one who gave Yuuna resolve to discover her true identity and prove her innocence, expressing how despite their rivalry, they become quite close as allies and friends.
Ouga Makyouin
Yuuna saw Ouga as dangerous rival for Kogarashi's affections after learning she was his first love. However, Ouga initially return to the land of the living under the suspicion that Yuuna was the evil force known as Garandou which destroyed many lives including taking Ouga's own life. This suspicion put her at odds with Yuuna as Ouga wanted to eliminate Yuuna. Ouga also knew Yuuna's real name was Tenko Genryuusai. Wanting to prove her innocence, Yuuna, with the help of her friends, try to flee from Ouga and discover the secrets of her pasts. Their chase ultimately reached a special spacial world created by a Tenko family member where the two finally reached a compromise when Yuuna unlocks a fragment of memories. Yuuna manages to subdue Ouga and explain how the Tenko family will prove she is not Garandou and when it's all over she will wash Ouga's back. After the learning the truth of Yuuna's origins and defeating the creator of the space, Byakuei Tenko, the true mastermind of Garandou, did Yuuna and Ouga finally got along. When Ouga finally passes on, Yuuna, along with Kogarashi and everyone else, all watched with closure as she disappeared.
Tenko Clan
Byakuei Tenko
Byakuei Tenko is Yuuna's creator and "Father". Byakuei created Yuuna as the 7th Clone of his daughter Mahoro Tenko. When first introduced, Byakuei says he only saw Yuuna as a mere failure among many clones in his attempts to save his daughter. Yuuna was visibly hurt by this revelation and is hurt even more on wondering on what his daughter would think of his actions. When Byakuei was finally defeated and revealed he had some level of care for Yuuna right before Kogarashi claims he would take good care of Yuuna, she was finally able to gain closure with him as he descended to the afterlife with Mahoro. Yuuna's respect for her father would have her attend an incoming funeral for Byakuei and Mahoro.
Mahoro Tenko
The original Yuuna Yunohana and her “sister”. Unlike her father, Mahoro treated Yuuna and the other Genryusai Clones like living human beings than substitute tools. This relationship is what lead Mahoro in stopping her father's plans and saving Yuuna and the others.
Previous Genryusai Tenko Clones
The six previous Genryusai Tenko Clones were Yuuna’s older “sisters” of her.
Nadare Tenko
The current head of the Tenko. They are at odds with each other as Nadare Tenko, under the orders of his family, is tasked with destroying her and the rest who lives in the Yuragi Inn. Nadare Tenko reveals that he actually has nothing against Yuuna and only sees her as a major obstacle in his orders to defeat Fuyuzora Kogarashi. This prompts Yuuna to be at further odds with Nadare as she would rather face death then being separated from Kogarashi. When she, along with Kogarashi, were finally able to defeat Nadare Tenko, they were able to put their differences aside when they both decide to help Nadare Tenko deal with the Tenko Elders, the ones responsible for the order to assassinate Kogarashi.