Isuna Hasekura is a Japanese novelist and manga author born on December 27, 1982, in Chiba Prefecture. He studied physics at Rikkyo University in Tokyo. Hasekura began writing fiction at the age of fourteen and started submitting his work to literary contests two years later. His professional career launched in 2005 when he won the Silver Prize in the twelfth Dengeki Novel Prize for his debut work, Spice and Wolf. The first volume of the light novel series was published the following year in 2006, marking his official debut as an author.

Hasekura is best known as the creator of the long-running Spice and Wolf franchise. The original light novel series, illustrated by Jyuu Ayakura, currently spans over twenty volumes and follows Kraft Lawrence, a traveling merchant, and Holo, a wolf harvest goddess, as they journey through a medieval-inspired world. The series has generated numerous adaptations, including multiple anime television series, a manga adaptation illustrated by Keito Koume, video games, and a sequel light novel series titled Wolf and Parchment, which focuses on the next generation of characters. The anime Wolf and the Amber-colored Melancholy is a short story adaptation within this same universe, originally appearing as a side story in the light novels that offered a narrative from Holo's perspective. Beyond Spice and Wolf, Hasekura created the manga Billionaire Girl, which tells the story of a successful young day trader and her college tutor. He also wrote the scenario for the three-part visual novel series World End Economica, set on a future lunar colony where the protagonist navigates stock markets to achieve his dreams. Hasekura has further expanded into virtual reality storytelling, working on the VR anime Project LUX and Spice and Wolf VR.

Several recurring themes and artistic identities are present across Hasekura's body of work. His stories frequently incorporate detailed elements of economics, trade, and market mechanics, reflecting his interest in historical commerce. The medieval European setting, which he has cited as a deliberate choice over a Japanese historical backdrop because he views Europe as a land of fantasy and inspiration, is another hallmark. Hasekura has stated that his inspirations for Spice and Wolf included Jean Favier's economic history Gold and Spices, James Frazer's mythological study The Golden Bough, and Moyoco Anno's manga Sakuran, which influenced the distinctive archaic speech patterns of his characters. A sense of melancholy regarding things left behind by progress is also a recurring emotional thread in his work. Within the industry, Hasekura is significant for the commercial and critical success of Spice and Wolf, which won the Kono Light Novel ga Sugoi! guidebook's top ranking in 2007 and has maintained a dedicated international following for nearly two decades. His career also demonstrates a notable willingness to explore different media, moving from light novels into manga, visual novels, and VR production through his involvement with the company Spicy Tails. He is a registered member of the Mystery Writers of Japan, and his pen name is derived from the character Hasekura Rei from the Maria-sama ga Miteru series.