Tsukune has a typical relationship with his parents and is a loving son. They were initially worried about Tsukune not being able to get into any high school until the faithful day that his father, Kōji, found a flier for Yōkai Academy. He kept his parents informed of his time at Yokai Academy (albeit without the details of the Yōkai there.) His father is never really shown in depth in the series aside from a few panels in the manga and a short one-liner at the end of the first season anime.
His mother, Kasumi, however, had a whole episode/chapter devoted to Tsukune coming home and meeting Moka, Kurumu, Yukari, and Mizore who all sneaked into Tsukune's house to spend time with him after the forced closure of Yokai Academy. The antics that followed deeply troubled her to the point of calling her husband in a panic to give Tsukune sex-education as soon as possible. After Kurumu, Yukari, and Mizore ran outside to continue their battle outdoors with Tsukune following, Kasumi had a one-on-one talk with Moka, who Tsukune would regularly tell her about. Pleased to know that there is someone there to take care of him, she leaves Tsukune in her hands while he's away at school.
Kyōko is Tsukune's older cousin, though they have a relationship akin to siblings. In their youth, Kyōko often dragged Tsukune into dangerous situations, but the two remained close. Kyōko affectionately calls Tsukune "Tsuki" while Tsukune calls her "Kyō-chan." Kyōko decided to come to Yōkai Academy to see if it is too dangerous during the School Festival. Kyōko got more than she bargained for and saw the true nature of the academy after receiving the Lilith's Mirror. However, after Tsukune rescues her from the mirror and the chaos that ensued, Kyōko realizes that Tsukune has grown up and doesn't need her to babysit him any longer. Kyōko promises to keep Yōkai Academy's nature a secret from Tsukune's parents because she trusts his decision to stay there.
There are hints that Kyōko may have developed some love for Tsukune after he carried her effortlessly in his arms. She noted that he's "so strong" with color in her cheeks.
Over the course of Tsukune's time at Yōkai Academy, Tsukune has managed to garner the affection of a few girls at Yokai Academy. This usually leads to the ire of most of the male student body as many of the girls are among the most beautiful in the entire academy. While his affections are mainly directed toward Moka, Tsukune has a tight relationship with each of the girls in his growing unintentional harem.
Moka Akashiya (Akasha Bloodriver/ Moka)Edit
Outer Moka is the very first student Tsukune met upon arrival at Yōkai Academy. Having fallen in love with her at first sight, Tsukune's thoughts are almost constantly about Outer Moka.
Moka’s initial attraction to Tsukune was due in part to his blood, which she considered “uniquely tasty.” Moka spent much of her time with him sneaking bites to drink his blood, much to his chagrin. In the anime, this was usually stylized as a "kiss bite" (accompanied with a "capu-chu" sound). Later, Tsukune began to tire of it since it immediately exhausted him of his energy each time she did it. Moka held herself back so he would not be upset. However, seeing Moka’s health deteriorate, Tsukune began to willingly allow her to drink his blood in moderation. Over time, Moka began to develop true affection for Tsukune and their feelings were mutual. In numerous instances, Tsukune and Moka nearly confessed to each other, but their attempts never happened either due to either being too shy to confess or were soured by the other girls who got in the way. When it appeared in the story that Tsukune will be expelled, Moka stated she would rather drop out and go with him, because she cannot bear the thought of being separated. Nevertheless Tsukune and Outer Moka's bond was strong.
After entering Moka's Rosario and seeing her past, Tsukune learns that the Outer Moka is nothing more than an artificial intelligence solely created to protect her Inner self. Despite dropping into a depression, Tsukune did not care if the outer one is a fake because he loves her all the same. After Alucard destroys the Rosario seal, mortally wounded, Outer Moka expresses her desire to be with Tsukune forever. The two confessed their love for each other and shared their first kiss before Outer Moka dies. He is willing to do anything for her, even becoming a true vampire to inject his blood into Moka to save her life.
Tsukune eventually learns the real truth that Outer Moka is a clone of Akasha Bloodriver after she erases her own memory, with all the moments of the time spent together with her up until her supposed "death", returning to Akasha's body. She remembers their love for each other, and thanks him for the happiness he's given her by having met him.
He realizes that he had fallen for Akasha's clone, or rather Akasha herself, from the very beginning on the first day they met; to which he was very thankful for. The only thing he regretted not saying back to her, before she finally disappeared. Tsukune still refers to Akasha Bloodriver/Outer Moka as "Moka-san", just as he always has. Although Tsukune's first love no longer exists, hints of her lives on in the real Moka.
Moka Akashiya (Inner Moka)Edit
Tsukune's initial thoughts of her was that she was both intimidating, but also beautiful. Inner Moka scolded Tsukune whenever he made her outer form upset and told him to be a bit more decisive with his feelings. Inner Moka did not consider Tsukune as anything special other than the means to remove the rosary to drive off the students that attacked her outer form, Tsukune, or both and as a source of sustenance through his blood, which she shared her preference for his blood. As the story progressed, Moka's initial cold attitude towards Tsukune warmed up to him little by little and eventually falls in love with him herself, but is too stubborn to admit it. When Tsukune was about to die after a brutal attack from ANTI-THESIS, Inner Moka injects him with vampire blood despite the possible consequence of turning him into a ghoul, saving his life at the cost of his humanity.
In their second-year, Tsukune began training with Inner Moka and Inner Moka's developing affections for Tsukune becomes more apparent as well as his own growing feelings towards her. Tsukune eventually learns that Inner Moka is the real Moka. When Inner Moka and Tsukune reunite at Fairy Tale Headquarters for the final battle, she opens her heart to him. Moka has shown indeed that she truly loves and wants to be with Tsukune. During the battle between Tsukune and Gyokuro, Tsukune began to descend into his ghoul form and Moka was very alarmed by this new development that was unintentionally caused by her transfusing her blood into him during their first year. Moka was willing to plead to Gyokuro if there was a way to save him. Despite Moka's despair at the apparent inability to save Tskune's remaining humanity and life, Tsukune was willing to give it all up if it meant her safety. After Tsukune managed to become a shinso vampire, Inner Moka planned to stay by Tsukune's side forever.
Ten months after the battle with Alucard, Moka and Tsukune begin their third year. Tsukune has very conflicting feelings since Moka has been displaying traits of the "Akasha" Moka. Those feelings were resolved when her father, Issa, talked to him about the one who actually died was actually Akasha, not Moka. After hearing Issa's words Tsukune realized that the Moka he had initially loved still lived somewhere in the current Moka's soul. Tsukune solidified this when he began to notice that Moka's silver hair had pale pink tips, signifying the merging of the two souls.
Tsukune first met Kurumu after hearing rumors of a girl who was seducing the male student body. Kurumu herself made advances on Tsukune after hearing that her main rival, Moka, who had stolen nearly all of the attention of the male students, was close to Tsukune. Though Kurumu had Tsukune under her Allure, Tsukune could not shake his thoughts of Moka. Angered, Kurumu tried to attack Tsukune only for Moka to step in and save him. Just as Inner Moka is about to mangle Kurumu, Tsukune stops her and tells her that he does not think that Kurumu is a bad person. Touched by his kindness, Kurumu develops true love and affection for Tsukune.
Tsukune and Kurumu's relationship afterwards is a completely friendly one, however Kurumu was very much in love with Tsukune. Kurumu was not above using her physical charms, often hugging Tsukune between her breasts, causing him to suffocate. She did, however, refused to use her succubi abilities to sway him, opting to win Tsukune over fair and square over her rivals. Because of Tsukune's love for Moka, Kurumu's affection for him goes generally unrequited. In their second-year after Moka is kidnapped by Fairy Tale, Kurumu reveals that Succubi live off of love, and with her generally one-sided love for Tsukune, her health drops. Shortly after, Tsukune loses control of his Shinso-Ghoul blood and goes berserk. Kurumu arrives at the site where Touhou Fuhai has been injured. Separated by a barrier, Touhou reluctantly decides to kill Tsukune. Horrified, Kurumu tries to break through the barrier, despite taking heavy damage. Fueled by her true love for Tsukune, she gives Tsukune his first kiss, stopping him long enough for Touhou to throw the final needle to seal Tsukune's power. Afterwards Tsukune and Kurumu share a tender, but a shy moment as Tsukune remembers being kissed by Kurumu, despite going wild by the Shinso blood. It is unclear as to the depth of Tsukune's affection for Kurumu after this, however Tsukune still has some affection for Kurumu as noted by Issa.
When Yukari was first introduced, she was only concerned about Moka, wanting to have her all to herself. She saw Tsukune as an obstacle standing in the way of her goals. Despite this, Tsukune held no ill will towards her, despite her constant pranks on him during this time. Tsukune helped save Yukari from prejudice monsters, accidentally gaining her affections in return. However, this lead to an unwanted change in her goals as now, Yukari wants to have a three-way relationship with Moka and Tsukune. As time went on, Tsukune began growing more and more frightened of Yukari due to her obsession to create a three-way relationship between them; however, he respects her knowledge and magic, which has helped them out of tight spots more than once.
Originally, Tsukune was targeted by Mizore because she thought he was lonely as her. At the very least, Mizore was interested in Tsukune, but after he saved her from Okuto Kotsubo (he molested her), Mizore fell in love with him. Mizore's stalker tendencies grew after she became a part of the group and she often throws ice kunais at any of the girls who get too close to Tsukune. Tsukune is often at unease while around her, especially when she brings up her desire to "make babies" with him, but he generally appreciates having her around.
Before the final battle against Fairy Tale, Mizore reveals that she does not care who Tsukune chooses in the end as she will always love Tsukune regardless and continue to follow him wherever he goes as his stalker.
Ruby is first met during the Newspaper Club's outing to the human world. Upon arriving at a Sunflower Patch known as the Witch's Knoll. There they meet Ruby, who attacks them because humans were planning on demolishing the Witch's Knoll. After knocking her out, Tsukune and the rest of the club take her to an inn and Tsukune apologizes for the actions the humans have done and Ruby begins to believe that humans and yōkai can coexist. After battling her master Lady Oyakata, Ruby spends some time recovering from the ordeal.
After Tsukune begins his descent into a ghoul, the Headmaster arrives with none other than Ruby to seal Tsukune's transformation. Ruby has revealed that she has developed feelings for Tsukune during her absence and works at Yōkai Academy to be close to him. Her relationship with him differs between the Manga and Anime. In the Anime, she tends to have a desire to be the more dominant personality over Tsukune while in the Manga, she tends to be more submissive, wanting him to be her "master." While Tsukune is disturbed by her sexual play advances, nevertheless, he likes Ruby as a friend.
Friend. Tsukune was originally at odds with Gin because of him wanting to date Moka. However, this problem dies out after the fight with the Security Committee. Tsukune respects Gin's noble and honorable side, but dislikes how much of a pervert his club president is.
Moka's younger half-sister. Kokoa is extremely protective and possessive of her older sister, Moka when she is in her monster form. She initially saw Tsukune as a baggage on her sister and tried her best to sever their ties to each other. However the two developed something akin to friendship during Kokoa's first few weeks at Yōkai Academy. Kokoa's hostility to Tsukune has lessened over time and she eventually works with Tsukune along with the rest of the Newspaper Club, which she joins.
Kokoa is notable as the only female character so far that has not shown any romantic affection for Tsukune.
Upon introduction, Fong-Fong desired to have Tsukune join his clan, the Huang Family. Unfortunately (and possibly humorous, depending on the reader) his recruitment speech was misinterpreted by everyone as a marriage proposal. Luckily, Koko and Ruby helped clear up the confusion. Fong-Fong entered Yokai Academy in search of strong monsters to recruit; however, he mistook Haiji and Gin's actions for Tsukune's. For much of his initial chapters, Tsukune saw Fong-Fong as a nuisance and, because of his awkward introduction, uncomfortable to be around.
By the time Fairy Tale kidnaps Moka, Tsukune is on better terms with Fong-fong, seeing him as a more reliable individual and true friend. It would seem Fang-fang finally gave up on trying to recruit Tsukune.
Hokuto was first seen by Tsukune as a strong and trustworthy individual. However, upon the revelation that he was masterminding ANTI-THESIS, Tsukune was crushed. During their battle, Hokuto revealed that he was once a human himself until he had monster blood injected into him like Tsukune. During their battle, Tsukune helped Hokuto see past his hatred of monsters and find the kindness in his own heart. After the battle, Hokuto went into hiding. Deep down, Tsukune still wanted to be his friend. During the Fairy Tale arcs, Hokuto became a valuable ally to Tsukune and his friends and helped him infiltrate Fairy Tale's headquarters and even offered his life to assist Tsukune in any way possible to reach Moka.
Tsukune met Akua in China at the Huang Family house when she came to take back Moka with her to Fairy Tale Headquarters. Tsukune saw Akua as a powerful enemy that he would have to face. Tsukune battled Akua at Fairy Tale HQ and knew that she wanted to separate him from Moka by trying to kill him, but fails to do so. Moments later, Akua offers to revive Moka and tries to make Tsukune leave believing that he can't save Moka due to him being human, however, when Tsukune mentions to her that their differences are not important, Akua in shock lets Tsukune revive Moka after he rips of his Holy Lock. Due to Tsukune's shinso power being out of control, Akua makes a magic spell circle to help him and her with Tsukune's friends give him the final push in becoming a Shinso Vampire. Tsukune somewhat sees Akua as an ally.
Issa is Moka, Kokoa, Kahlua, and Akua's father. Tsukune did not formally meet him until the series epilogue. Moka brought Tsukune to meet him, but Tsukune was intimidated by Issa. With each innocent statement, Tsukune appeared to have continuously annoyed and infuriated him. Unfortunately Tsukune's harem made an untimely appearance in front of Issa, further infuriating him. Initially it had seemed that Issa had come to assassinate Tsukune and the constant mishaps solidified his resolve to kill him, however, his true purpose was to protect him from Fairy Tale hired assassins and to train him to utilize his Shinso powers properly.
During their first training session together, Issa obliterated Tsukune in a mere 30 seconds. After the fight, he revealed that his attitude when they first met was just simply hazing. Remembering a question he brought up at the bar, Issa noted that Tsukune had some conflicted feelings since his affections for Akasha/Outer Moka still remained. He told him that the soul of the Outer Moka still exists in Moka's soul and will remain there as long as he continued to think about her. Issa also lamented the results of him being a polygamist and warned Tsukune to be careful with his harem.
Shizuka Nekonome is Tsukune's teacher.