Kou Yoneda is a Japanese manga artist and illustrator known for her significant contributions to the boys' love genre. Born on December 28, 1985, in Osaka Prefecture, Yoneda first began creating manga professionally as a doujinshi artist under the circle name Nitro Koutetsu. She made her commercial debut in 2008 with the one-shot Doushitemo Furetakunai, published in the magazine Craft. This work, also known as No Touching at All, was met with immediate critical acclaim and helped establish her reputation for realistic, emotionally nuanced storytelling.

Yoneda is best known as the creator of the ongoing manga series Saezuru Tori wa Habatakanai, which is published in English as Twittering Birds Never Fly. The series began serialization in the magazine ihr HertZ in August 2011. The story is set within the yakuza underworld and follows the complex relationship between Yashiro, a masochistic young crime boss, and Chikara Doumeki, his stoic and impotent new bodyguard. The manga is noted for its unflinching examination of trauma, power, and emotional repression, moving away from idealized romantic tropes to present deeply flawed and psychologically realistic characters. The first volume of the series includes two earlier one-shot stories by Yoneda that serve as prequels: Don't Stay Gold, originally published in 2008, and Though They Drift, They Do Not Sink, But Nor Do They Sing, originally published in 2009. These stories expand the narrative universe by exploring the histories of supporting characters.

The popularity of Twittering Birds Never Fly led to a multi-media franchise. It was adapted into a series of audio dramas beginning in 2013. The manga was subsequently adapted into an anime film trilogy produced by the Blue Lynx label. The first film, Twittering Birds Never Fly: The Clouds Gather, was released in 2020. A related original animation DVD adapting the prequel story Don't Stay Gold was released in 2021. The sequel film, Twittering Birds Never Fly: The Storm Breaks, has also been announced. Yoneda is credited as the original creator for all these anime productions, including the example works listed by the user.

Beyond her most famous series, Yoneda's body of work includes several other notable titles that have been adapted into drama CDs. Her debut work, Doushitemo Furetakunai, was adapted into a live-action film in 2014. She also authored NightS, a collection of short stories published in 2013, and Soredemo, Yasashii Koi o Suru, a spin-off of her debut work published in 2014. Her first art collection, titled 20072017, was released in 2017. Expanding beyond the boys' love genre, Yoneda began serializing the seinen manga Op -Op- Yoake Itaru no Iro no Nai Hibi in Kodansha's Evening magazine in 2018.

Yoneda's artistic identity is characterized by a gritty, mature aesthetic and a focus on psychological depth. Her narratives are praised for their realism, subtle character development, and melancholic atmosphere. She frequently explores themes of moral ambiguity, the lasting effects of past trauma, and the difficulty of forming genuine human connections. Her work has received numerous accolades, including the FRaU Manga Award in 2015 for Twittering Birds Never Fly and consistent top rankings in the annual BL Awards hosted by the Japanese review site Chil Chil. Her ability to craft complex, character-driven stories has made her a highly respected and influential figure in contemporary manga.