Tsubasa Yamaguchi is a Japanese manga artist born on June 26 in Tokyo. She is a graduate of the Tokyo University of the Arts, a prestigious national fine arts university, an educational background that has heavily influenced her creative work. Her career began with the publication of one-shot stories such as Nude Model and Onna no Ko in Kodansha's Good! Afternoon magazine in 2015. In 2016, she launched her first full serialized series, a manga adaptation of Makoto Shinkai's animated short She and Her Cat, which was published in Monthly Afternoon.

Yamaguchi is best known as the creator of Blue Period, which began serialization in Monthly Afternoon in June 2017. The series follows Yatora Yaguchi, a high school student who discovers a passion for art and strives to enter the Tokyo University of the Arts. The manga achieved significant critical acclaim, winning the 13th Manga Taishō award and the 44th Kodansha Manga Award in the general category, both in 2020. It was also nominated for the Tezuka Osamu Cultural Prize. The success of the manga led to an anime television series adaptation that premiered in October 2021.

The creator's artistic identity is deeply rooted in her personal history. Her experiences as a student at Tokyo University of the Arts directly informed the setting and central themes of Blue Period. In interviews, she has noted that the main character, Yatora, feels the most familiar to her, as she also navigated the challenges of an art school education. Beyond the narrative, she has discussed how her own struggles with artistic identity and creative expression are woven into the story, drawing inspiration from personal experiences and those of friends to develop characters like Yuka.

Regarding her creative process for Blue Period, Yamaguchi has described a monthly schedule that involves a week for storyboarding and drafting, followed by a week and a half for drawing, with the remaining time used for revisions. She works with assistants who help with backgrounds and inking, and she often uses friends or herself as a reference model for difficult elements like hands and feet. To accurately depict the wide variety of art styles within the manga, she collaborates with other artists, including former classmates, to create the original works attributed to the characters.

Yamaguchi's industry significance extends beyond her award-winning work. She is known for maintaining a degree of anonymity in public appearances, often wearing a frog mask during events. In a published interview, she explained that this practice, along with using the gender-neutral given name Tsubasa, is a deliberate choice to navigate the Japanese publishing industry, where some readers might make assumptions about a creator's perspective based on gender. This approach allows her work to be received without such preconceptions. Her contributions to the medium also include illustrating the light novel Anata wa Koko de, Iki ga Dekiru no? by author Fuyumi Takabayashi.