Kōta Amana is a Japanese manga writer best known as the original creator of the manga series Vermeil in Gold. The series, which began serialization in Square Enix's Monthly Shōnen Gangan magazine on August 10, 2018, is written by Amana and illustrated by Yōko Umezu. As of October 2025, the manga has been compiled into ten tankōbon volumes. The story follows a young magician who accidentally makes a contract with a powerful female demon, leading to a symbiotic relationship that blends magical combat with romantic comedy elements.

The Vermeil in Gold manga received an anime television series adaptation produced by Staple Entertainment, which aired from July to September 2022. The twelve-episode series was directed by Takashi Naoya, with Tatsuya Takahashi handling series composition. In this adaptation, Amana is credited as the original story author.

Beyond Vermeil in Gold, Amana has been credited as the author or original creator for several other manga and light novel series. These include the manga Gensou Gourmet, which ran from 2016 to 2020, the manga Kono Yuusha, Moto Maou ni tsuki, serialized from 2022 to 2023, and the light novel series Hiten no Asuka: Isekai no Shoujo ni Saikyou Hougu Ataeta Kekka. Additional works associated with Amana include the manga Kenhijiri no Shougou wo Motsu Ryourijin, the light novel series Isekai Concierge: Neko no Shippotei Eigyou Nisshi, and the more recent series Ore ni Tsugou ga Yosugiru Machi: Shihaisha Skill de Isekai Harem Musou, which began in 2026.

Amana's writing is primarily situated within the fantasy and romantic comedy genres. His narratives often focus on the development of intimate, symbiotic relationships between characters from opposing backgrounds, such as a magician and a demon, subverting traditional master-servant dynamics in favor of partnerships built on mutual need and emotional connection. Themes of outcasts finding strength in each other and the navigation of complex moral dilemmas regarding power and identity are recurring elements in his work. Within the industry, Amana is recognized for his contributions to the ecchi-fantasy subgenre, particularly through the success and adaptation of Vermeil in Gold, which brought his style of balancing high-stakes magical settings with character-driven interpersonal tension to a wider audience.