Fujita is the creator of the manga series Wotakoi: Love is Hard for Otaku, which began as a self-published work on the Japanese art platform Pixiv. The creator, who uses the mononym Fujita, started posting one page at a time on the site as a hobby, driven by a personal desire to rediscover the joy of drawing manga after a difficult period in their career. The positive response from readers led to the series being discovered by the publisher Ichijinsha, and it was eventually serialized in the collaborative web magazine Comic Pool starting in November 2015.

The original manga, which Fujita both writes and illustrates, ran from April 2014 to July 2021 and was collected into eleven tankōbon volumes. The series follows the romantic and comedic daily lives of two otaku office workers, Narumi Momose and Hirotaka Nifuji, who begin dating in an effort to find a relationship with a partner who understands their respective hobbies. The story expands to include their colleagues, Hanako Koyanagi and Tarō Kabakura, a married couple who are also fellow otaku. Fujita has stated that the idea for the series came from a casual conversation with a friend about what kind of scenarios would be cute for a couple, and that the characters were not directly based on real people but rather on archetypes the creator felt must exist.

The success of the manga led to a significant adaptation history. An eleven-episode anime television series produced by A-1 Pictures aired from April to June 2018 on Fuji TV's Noitamina programming block. Following the anime, three original video animation (OVA) episodes were released between 2019 and 2021, bundled with limited edition volumes of the manga. The franchise was further adapted into a live-action film that premiered in February 2020 and a stage play that ran in May 2022. Regarding the anime, Fujita has expressed happiness at seeing the passion of everyone involved in its production and has noted the enjoyment of watching overseas reaction videos.

Fujita's artistic identity is characterized by a focus on comedy and lighthearted, character-driven storytelling. The creator cites comedic influences such as Gintama and the works of Rumiko Takahashi, specifically Ranma 1/2 and Maison Ikkoku, as ideal examples of the energy they wanted to create. Fujita aims to keep the tone of their work light and not too serious, taking care to develop characters that readers will find endearing. In terms of technique, Fujita prefers a hybrid approach, using analog tools for inking to achieve a convincing look and a sense of the finished product, while employing digital methods for background art, which is seen as more efficient.

The creator's path to professional success is notable for its origin as an amateur posting on Pixiv, a platform that was just beginning to be recognized as a source for undiscovered talent at the time. This trajectory highlights a significant shift in the manga industry, where web comics and self-publishing have become viable routes to major serialization and multimedia franchises. Wotakoi achieved substantial commercial success, with over ten million copies in circulation by August 2020, and has been licensed for English release by Kodansha USA. The series also received the Next Manga Award in 2014 and topped the women's category of the Kono Manga ga Sugoi! ranking in 2016.