Mahiru Seki

Mahiru Seki was a former middle school student and a childhood friend of Kou Yamori and Akira Asai. Despite the positive reputation he had a school, Mahiru was secretly somewhat vain and only enjoyed the company of Kou and Akira. While working at his family flower shop, Mahiru met Kiku Hoshimi, a vampire who eventually developed a relationship with him. Seeking to become a vampire himself to evade his everyday life, he started dating Kiku, and as time passed, Kiku had Mahiru completely struck with love and abiding to her influence.

Willing to enact Kiku's wish to become human and follow her words, Mahiru discarded all of his close friends and belongings so that his mind could only be locked onto Kiku, who in turn also fell in love with him. When the couple was being chased after by Kou, Nazuna Nanakusa, and Kyouko Mejiro, Mahiru and Kiku fled to Hokkaido, where they prepared for Kiku's theoretical conversion. There, Mahiru met Kou and Akira again and reconciled with them. Though he promised to stay friends with them after becoming a vampire, he couldn't let go of Kiku and died with her at sunrise.

Appearance
Mahiru is a young boy with a darker faint skin tone who usually wears his school uniform consisting of a gray blazer, under which he wears a red hoodie, gray pants, and white tennis shoes. His hair is dark blonde and tied in a little ponytail.

After choosing to become a vampire, he lets his hair down and starts to wear baggy clothes, described by Kou as "looking tired."

Personality
Mahiru is a kind person that tries to keep a good and relaxed atmosphere with the people around him, able to socialize with his classmates and teachers, making him very popular in school.

But that's a facade under which lies a depressed and traumatized person who resents his family for the emotional abuse they put him through. He genuinely loves flowers and hoped to inherit his parents' flower shop as a child. But later, he ended up hoping the shop would vanish along with his household. Similar to Kou and Akira, his only genuine friends, socializing with his schoolmates is not fun to him. He is tired of constantly being pressured to spend time with them and feels a catharsis after telling them his real feelings, despite getting beaten up by them. Mahiru was a timid and quiet child but started copying his brother's personality after he died so he could become popular. Despite not seeing them as real friends, Mahiru felt lonely without the other students.

During his time spent with Kiku Hoshimi, Mahiru undergoes a dramatic personality change, becoming rude, blunt, violent, and enthusiastic about killing humans. However, it turns out that he acted that way because he was distressed by Kiku's looming death. After fighting with Kou, he mellows out. His depression has become more apparent; his words often have a melancholic undertone, and he isolates himself from everyone except Kiku. Despite being willing to abandon his friends and family, he is still attached to Kou and Akira.

Family

 * Mr. Seki - Father
 * Mrs. Seki - Mother
 * Shougo Seki † - Brother

Allies

 * Kou Yamori - Former Classmate and Friend
 * Akira Asai - Former Classmate and Friend
 * Kiku Hoshimi † - Girlfriend and Love Interest
 * Akihito Akiyama
 * Hatsuka Suzushiro
 * Nazuna Nanakusa - Former Enemy and Friend

Enemies

 * Michihisa Kanou †
 * Kyouko Mejiro

Kou Yamori
Kou and Mahiru are childhood friends. He felt like he could be himself around Kou when they were little. Despite that, he kept copying his brother's personality and didn't tell Kou the truth about his family. Mahiru was envious of Kou since he felt lonely without others, while Kou never seemed bothered when he was alone. He also respected him since Kou didn't need to rely on others. They understood each other well, and Mahiru often thought of him after Kou dropped out of school. After a vampire assaulted Akira, Mahiru opposed the idea of Kou becoming one and scolded him. Later, he learned to accept it and offered Kou to drink his blood if he became a vampire. While initially confused by Kou's lack of hesitation, Mahiru soon understood Kou's reason and used it as a motivator to become a vampire himself, even proposing they compete over who gets to become one first.

After Mahiru decided to become Kiku's servant, their relationship drastically changed for the worse. He enjoyed toying with Kou as they talked and kept creeping him out with his radical personality change. He felt upset when Kou took Anko Uguisu's side and suggested that Mahiru was just being used by Kiku, beating him up. When Kou turned into a half-vampire and almost killed him, he felt betrayed because Kou didn't tell him about his powers before and revealed that he was incredibly jealous of him for "being special," ending their friendship on the spot.



He later gave an indirect hint of where he was headed, seemingly inviting Kou, and was shown to still care about him as he valued a photograph of himself, Kou, and Akira too much to burn it. It was revealed that Mahiru regretted how he treated Kou and was happy that he came to see him. However, because of a misunderstanding, Mahiru was scared of Kou and thought he wanted revenge, causing him to run away from Kou in fear.

Later, after an awkward start, the two friends reconciled, with Mahiru apologizing to Kou for hitting him, even proposing to get punched for it. After Kou explained that he wasn't intending to hurt him and gave him one of the two bokuto he bought, Mahiru offered it back since he was already too emotionally attached to it. He explained that while Kou and Akira meant a lot to him, he always wanted to escape his home and that Kiku only sped up the process. Following Akira's suggestion. Mahiru wanted to spend the remaining school trip with her and Kou after becoming a vampire, saying that he wanted to try a seafood bowl. While walking away with Kiku, Mahiru used the opportunity to brag to Kou that he was the winner of the two.

However, he was unable to let go of Kiku and apologized to Kou and Akira before turning to dust.

Kiku Hoshimi
They met when Mahiru delivered flowers to Kiku and started meeting from then on. Kiku tells him the words he wants to hear and listens to everything he says, including his worries, making him feel fulfilled and understood and falling in love with her. That led him to stay with her even after she was revealed to be a vampire, despite witnessing a vampire almost kill someone close to him. Thanks to Kiku's manipulation, Mahiru was willing to leave behind everyone he knew and wanted to protect her life and secrecy at all costs. Mahiru was shown to be frustrated because she still hadn't turned him into a vampire, but he said that, while he'd like to become one, he was fine with it not happening as long as he got to stay at Kiku's side.



He was not entirely himself because of Kiku's vampiric charm, which, as he described, decreased his capability to think and put him in a state of euphoria. Despite his loyalty, Mahiru was willing to go against her wishes and secretly kept a photo from his past, even though Kiku wanted him to burn his past belongings. He wasn't afraid to confront her when he noticed her keeping secrets, insisting that Kiku talked to him properly.

As it turned out, Kiku met Mahiru many years ago, shortly after his brother died. Kiku saw him in the same spot for multiple days and eventually decided to approach him. Mahiru confessed to her how he felt about his family and their neglect and asked if it was okay for him to hate his parents. After she reassured him that it was, Mahiru asked for her name, to which she replied by asking if he was hitting on her at such a young age, to which he reacted by blushing.



It was revealed that, on Halloween, Kiku told Mahiru that she would die soon and that she wanted to die as a human with him killing her. He was heavily upset but eventually accepted it, as according to Kiku herself, she would die soon, no matter what. Mahiru knew that Kiku might be lying to him but trusted her because he loved her. He didn't care that Kiku might trick him, as she was everything to him. In the end, Mahiru chose to die with the love of his life instead of living on without her.

Akira Asai
Mahiru wasn't initially close with Akira, calling her an idiot when they were young children. Still, they eventually became genuine friends, feeling a connection they didn't have with anyone else due to their similarities. She, along with Kou, was one of the most important people in his life. They hung out at school, and Mahiru talked with her about the things going on in his life, like him dating someone. After Akira almost got killed by a vampire, his opinion of vampires turned negative for a while, and he didn't want Kou to become one. He later consulted Akira about becoming a vampire and shared his worries with her. After joining Kiku, he was still on relatively good terms with her before bidding her farewell. As he burned his past belongings to eliminate his future vampiric weaknesses, he looked at a photo he had taken with Akira and Kou and decided to keep it.

Mrs. Seki
After his brother's death, Mahiru was constantly neglected by his mother, who kept hoping that her older son would return one day. Ever since that happened, Mahiru's room was never changed and years later still looked like the typical room of an elementary school student. Mahiru wasn't allowed to go on a school trip because "his brother wasn't going." This treatment caused Mahiru's frustrations to build up and eventually turn into silent resentment. He still cared about his mother, helped his parents in the flower shop, and made excuses for his mother's abusive behavior, believing she was broken from the shock.



After Kiku confronted her and explained that she was aware that Shougo was dead but didn't want to accept it, Mahiru reflected on his past and confessed to his mother that he used to hate her to the point of feeling exhausted but that he doesn't feel that way anymore. He explained that he now felt nothing for her and used the opportunity to taunt her with a smile before leaving his family for good.

In a letter he sent to Kou before his death, he confessed that he first planned to kill his parents after turning into a vampire, but that he changed his mind. Acknowledging that it was too late for him and his family to reconcile, he hoped they would move on and live happy lives.

Abilities
As an average human, Mahiru doesn't possess any extraordinary abilities.

Trivia

 * Mahiru wasn't featured on any volume cover until Volume 17 came out but was featured on the cover of the official fan book.
 * Mahiru confessed that he does stare at attractive people's bodies and knows how not to get caught.

Quotes

 * "Farewell, mom. Don't worry, I'm sure, Nii-san will come back. Just stay patient, like you've been until now."
 * "Cleaning up my personal affairs before becoming a vampire is a lot like preparing for suicide, huh..."