Keiko Sahara, an ordinary office worker whose passion is designing cute gel nails, is suddenly transported to a fantasy world where a persons magical ability is channeled through the art painted on their fingernails. In this realm, the profession of Nail Painter or nail artist is a respected magical discipline, and Keiko, soon nicknamed Saara, finds her hobby has become the key to her survival. After a local magic nail artist recognizes her potential, she is taken in as his apprentice, beginning a new life in the small eastern city of Srugia.

The setting is a world where nail polish acts as a magical conduit, and the intricate designs applied by artists like Saara directly determine the power and effectiveness of a spellcasters abilities. The story revolves around Saaras determined effort to navigate this unfamiliar society, working as a below-average nail artist who dreams of becoming the worlds first decorated nail artist, creating designs that are both beautiful and powerful. Her journey is guided by her grumpy goblin mentor, Master Reed, a skilled craftsman who values practicality over aesthetics and whose own magic nails are brutally effective but visually plain. Saaras primary client and biggest critic is Rocco, a stunningly beautiful and immensely powerful wizard with a sadistic personality. He is fascinated by Saaras purely decorative nails, which are nearly useless for casting spells, and hires her services largely to amuse himself by witnessing her shortcomings. Rounding out the main cast is Roccos earnest apprentice, Hou, who often finds himself exasperated by his masters cruelty and tries to support Saara in her technical education.

The narrative follows Saaras growth as she learns the fundamental differences between practical magic-nails and decorative ones. An early notable arc involves her first expedition to the "Immortal Forest" to gather materials, where she is nearly killed by a giant beast until Rocco saves her. He forces her to use her own unsatisfactory explosive magic nail in combat, mocking its weakness but showing her the harsh reality of her current skill level. Instead of being crushed, she becomes energized with a clear goal. In another story arc, Saara ignores warnings and travels alone through a dangerous district at night, only to be kidnapped. Rocco rescues her again, philosophizing about the moons guiding thread of fate, which is the core tenet of the local "Moonlight Faith" religion. Throughout these adventures, Saara works to prove that her "cutesy" designs can be more than just party tricks, aiming to surpass her master and revolutionize how magic is wielded in this foreign land.