It was serialized on the Twi4 Twitter account and Saizensen website, usually as a single-page four-panel strip, from April 2015 to July 2019.

Tomo Aizawa is a tomboy who has been head-over-heels in love with her childhood best friend Junichiro Kubota for a long time, even though he only sees her as "one of the boys" and has no romantic feelings for her at all.

Tomo-chan Is a Girl!, written and illustrated by Fumita Yanagida, was serialized on the Twi4 Twitter account and on the Saizensen website from April 7, 2015, to July 14, 2019.

[19] When Junichiro and Misuzu both forget their umbrellas on a rainy day, they wait to see who Tomo will pair up with.

Tomo thinks it is a challenge to fight, but they tell her they like Kousuke, so she feels flattered they are going to her for love advice and supports them.

[39] Rie Takahashi, Rina Hidaka, and Sally Amaki performed the ending theme song "yurukuru＊love" from Episodes 2–9 and 11–13,[39] while Kaito Ishikawa, Kōhei Amasaki, and Yoshitsugu Matsuoka performed the ending theme song "Jiribaki_love" for Episode 10.

[3][41] Tomo Aizawa, a tomboy, unsuccessfully confesses her love to her childhood friend Junichiro Kubota.

Later on, after Tomo asks her best friend Misuzu Gundou for advice, she tries to change the way she talks with Junichiro, but they instead fight.

Tomo bolts away after Junichiro comes close to prevent her from getting wet, and he does the same thing after he accidentally sees her soaked clothes.

After Tomo gets groped by an old man on the bus, Junichiro restrains him and later suggests that she wear slacks instead of a skirt.

Carol invites Tomo and Misuzu to her house, which turns out to be a giant mansion with a maze-like front yard.

Junichiro helps her up and walks to a park with her, not realizing that the girl is Tomo, even after she responds to subtle questions about their relationship.

Tomo continues playing said handheld in the present, wondering when Junichiro will come to take it back.

The two of them easily race past the rest of their class, but on the way back, Tomo collapses from exhaustion, revealing that she also ran for hours the night before.

When Junichiro later visits Tomo, she gives him back his handheld from years ago, claiming that he finally caught up to her in physical prowess.

Tomo gets a part-time job at a ramen shop owned by Tatsumi's family, with Misuzu as a waitress and Carol playing a mascot.

As part of Anime News Network's Fall 2018 manga guide, Rebecca Silverman, Amy McNulty, Faye Hopper, and Teresa Navarro reviewed the first volume for the website.