Izumi Tsubaki is a Japanese manga artist known for creating the popular romantic comedy series Monthly Girls' Nozaki-kun. Born on December 11 in Saitama Prefecture, she holds teaching licenses for elementary, middle, and high school, a background that has subtly influenced some of her work. Her career in manga began early; she started drawing in her first year of high school and won a contest judged by Hakusensha in her third year. Tsubaki is also the older twin sister of fellow manga artist Yoshiki Koga, whom she often thanks in her published works. She has cited Yoshihiro Togashi, creator of Yu Yu Hakusho, as a major inspiration, noting that his series was the first manga she ever bought with her own money.

Tsubaki made her professional debut in 2002 with a one-shot titled Chijimete Distance, published in Hana to Yume magazine. Her first serialized work was Oyayubi kara Romance, also known as The Magic Touch, which ran from 2003 to 2007. This series, focused on a high school girl obsessed with massage and shiatsu, was inspired by her own experiences in a kempo martial arts club where she learned the technique. Following this, she began Oresama Teacher in 2007, a long-running comedy about a former delinquent trying to live a normal high school life. The series concluded in 2020 after a total of 29 volumes and has been released in English by Viz Media.

Tsubaki’s most internationally recognized work is Monthly Girls' Nozaki-kun, a four-panel comic strip that began serialization in 2011. Unlike her previous works, which were published in the shojo magazine Hana to Yume, Nozaki-kun is published in Gangan Online, a magazine targeting a male demographic. The series was adapted into a twelve-episode anime produced by Dogakobo, which brought the story of a hapless high school girl and her oblivious manga artist crush to a wide audience. The English translation of the manga is published by Yen Press.

Despite being categorized as a shojo author, Tsubaki’s work is known for its heavy use of comedy, parody of romantic tropes, and characters with exaggerated, unique personalities. Her clean, expressive art style and focus on sustained misunderstandings and gag-driven plots have earned her a significant fanbase across both male and female readers. Her ability to blend the emotional introspection of shojo with the pacing and action of shonen, as seen in the delinquent battles of Oresama Teacher, defines her artistic identity.