As Kobayashi sets off for another day at work, she opens her apartment door only to be met by an unusually frightening sight—the head of a dragon, staring at her from across the balcony. The dragon immediately transforms into a cute, busty, and energetic young girl dressed in a maid outfit, introducing herself as Tooru. It turns out that the stoic programmer had come across the dragon the previous night on a drunken excursion to the mountains, and since the mythical beast had nowhere else to go, she had offered the creature a place to stay in her home. Thus, Tooru had arrived to cash in on the offer, ready to repay her savior's kindness by working as her personal maidservant. Though deeply regretful of her words and hesitant to follow through on her promise, a mix of guilt and Tooru's incredible dragon abilities convinces Kobayashi to take the girl in. Despite being extremely efficient at her job, the maid's unorthodox methods of housekeeping often end up horrifying Kobayashi and at times bring more trouble than help. Furthermore, the circumstances behind the dragon's arrival on Earth seem to be much more complicated than at first glance, as Tooru bears some heavy emotions and painful memories. To top it all off, Tooru's presence ends up attracting several other mythical beings to her new home, bringing in a host of eccentric personalities. Although Kobayashi makes her best effort to handle the crazy situation that she has found herself in, nothing has prepared her for this new life with a dragon maid. [Written by MAL Rewrite]

Futaba Yoshioka used to be an attractive and popular middle-schooler—well liked by the opposite sex, but ostracized by the girls. Nevertheless, she was able to brush all that off, because the only opinion that truly mattered to her was that of Kou Tanaka, a classmate with whom she shared a shelter from rain once, followed by quite a few other precious and significant memories. She even succeeded at making plans to meet with the quiet and innocent boy at the summer festival, but a simple misunderstanding, and Tanaka's subsequent disappearance, left her walking the halls of her school friendless. Now in high school, Futaba is not your typical adolescent girl. Determined to become a class favorite this time, she avoids all unwanted attention and, instead of acting cute and feminine, only stands out through her tomboyish behavior and disheveled look. But still, her world is soon turned upside down when the only boy she ever liked unexpectedly comes into her life once again—except he goes by the name of Kou Mabuchi now, and it is not his name alone that has gone through a sea change. [Written by MAL Rewrite]

Mirai Kuriyama is the sole survivor of a clan of Spirit World warriors with the power to employ their blood as weapons. As such, Mirai is tasked with hunting down and killing "youmu"—creatures said to be the manifestation of negative human emotions. One day, while deep in thought on the school roof, Mirai comes across Akihito Kanbara, a rare half-breed of youmu in human form. In a panicked state, she plunges her blood saber into him only to realize that he's an immortal being. From then on, the two form an impromptu friendship that revolves around Mirai constantly trying to kill Akihito, in an effort to boost her own wavering confidence as a Spirit World warrior. Eventually, Akihito also manages to convince her to join the Literary Club, which houses two other powerful Spirit World warriors, Hiroomi and Mitsuki Nase. As the group's bond strengthens, however, so does the tenacity of the youmu around them. Their misadventures will soon turn into a fight for survival as the inevitable release of the most powerful youmu, Beyond the Boundary, approaches. [Written by MAL Rewrite]

Nana Komatsu is a helpless, naïve 20-year-old who easily falls in love and becomes dependent and clingy to those around her. Even though she nurses ambitious dreams of removing herself from her provincial roots and finding her true calling, she ends up traveling to Tokyo with the humble reason of chasing her current boyfriend Shouji Endo. Nana Osaki, on the other hand, is a proud, enigmatic punk rock vocalist from a similarly rural background, who nurtures the desire to become a professional singer. Putting her career with a fairly popular band (and her passionate romance with one of its former members) firmly behind her, she boards the same train to Tokyo as Nana Komatsu. Through a fateful encounter in their journey toward the metropolis, the young women with the same given name are brought together, sparking a chain of events which eventually result in them sharing an apartment. As their friendship deepens, the two attempt to support each other through thick and thin, their deeply intertwined lives filled with romance, music, challenges, and heartbreaks that will ultimately test their seemingly unbreakable bond. [Written by MAL Rewrite]