Tsubomi Tachibana is a fifth grader dealing with rather sensitive issues such as her mother's pregnancy, her first period and the strange feelings she has started to get when she has been around boys. (Source: ANN)

One Night Sake Cup On his way back home from an errand, Takashi Natsume gets lost in the forest. Luckily, he is rescued by a traveling youkai couple who make sake cups for a living. Taking a sip of water from one, Natsume feels a surge of energy rush throughout his body, thanks to the One Night Cup. It is a special cup that makes every drink delicious, but unfortunately, its effects last only for one night. The following day, Natsume attends the youkai banquet with his loyal protector, the sake-loving chubby cat Madara, and gets the once-in-a-lifetime opportunity to learn how to make sake cups. Party of Fun & Games Natsume is filled with regret after hastily declining a rare invitation to a banquet from Madara. Curious, he chases after the cat to an old, run-down mansion but soon enough feels the uncanny presence of numerous youkai nearby. When he runs into the seductive youkai Hinoe, she explains that the empty estate serves as a hide-and-seek playground where the winning spirit acquires authority over a valley. With still no trace of Madara, Natsume starts having eerie dreams of the mansion, but this time as the game's participant.

Blessed with eyes that are able to perceive the otherwise invisible youkai, Takashi Natsume hides his ability from his newfound family and friends to protect everyone's peaceful daily life. Nonetheless, Natsume never fails to show the same kindness to the benevolent youkai and happily returns their names by using the infamous Book of Friends he inherited from his late grandmother, Reiko. Meanwhile, the exorcist clan Matoba still wishes for Natsume to join their ranks due to his overwhelming gift. However, Natsume firmly rejects the clan's invitation since not all exorcists are as reasonable as his friend Shuuichi Natori, and many improperly and indiscriminately seal away every youkai in their way. Unsatisfied with Natsume's answer, Seiji Matoba blackmails Natsume into attending a grand gathering of powerful exorcist families. Natsume soon finds himself in the company of dangerous people and youkai alike. But even then, he continues to defy the exorcists' hard-handed methods and believes that peace between both worlds is possible.

Takashi Natsume and his spirit companion Madara, nicknamed Nyanko, continue returning the names of spirits from the Book of Friends given by his late grandmother Reiko Natsume. On his way back from school one day, Takashi encounters a lurking spirit named Monmonbou, who recalls memories of Takashi's grandmother after hearing his name. Takashi's natural curiosity leads him to explore a mysterious town where his grandmother used to live. Befriending her old acquaintance Yorie Tsumura and Yorie's son Mukuo, Takashi unveils more of his grandmother's past. In the meantime, Nyanko detours for food and stumbles upon a suspicious Spirit Seed, which miraculously sprouts into a fruit tree overnight. Giving in to temptation, Nyanko consumes the fruit, splitting him into three. Seeking a solution to Nyanko's predicament, Takashi and his friends lend a hand, unexpectedly uncovering more secrets the town holds in the process.