Yasunori Mitsunaga is a Japanese manga artist best known for creating the series Princess Resurrection, also known as Kaibutsu Ōjo. Born in Hamamatsu City in Shizuoka Prefecture, he moved to Tokyo to pursue a career in manga and worked as an assistant to the manga artist Yuu Nakahara. He has also used the pseudonym Tsunagami. Early in his career, he cited Fujiko Fujio's Doraemon as a major inspiration, which he read during a childhood hospitalization.

Mitsunaga's most significant and enduring work is Princess Resurrection, which he wrote and illustrated. The manga was serialized in Kodansha's Monthly Shōnen Sirius magazine from June 2005 to February 2013 and was collected into 20 tankōbon volumes. The series follows Hiro Hiyorimi, a boy who is revived as a half-immortal servant to Hime, a princess of the Monster Realm who is a contender for her kingdom's throne. Princess Resurrection was adapted into a 26-episode anime television series produced by the studio Madhouse, which aired in 2007. This was followed by a three-episode original video animation series produced by Tatsunoko Production, released between 2010 and 2011. The manga and its adaptations established his reputation for blending horror, comedy, and supernatural action.

Following the conclusion of Princess Resurrection, Mitsunaga continued to work within its universe. He wrote a spin-off series titled Naqua-Den, which ran from 2012 to 2014, and a direct sequel, Princess Resurrection Nightmare, which was serialized from November 2017 to March 2021. His other notable original works include the series Time Stop Hero, which began serialization in 2020, and Avarth, which ran in 2016. He has also worked as the original story writer for several manga illustrated by other artists, including Tama Kick and Evil Heros. More recently, he is credited as the creator of the series Stella Must Die, for which he provides the story while Ine Ohtaka handles the art.

Mitsunaga's artistic identity is characterized by a unique drawing style that has been noted to change considerably in anime adaptations, such as with Princess Resurrection, though the OAD version was noted to more faithfully preserve his original artwork. His stories often feature darkly comical tales with supernatural elements and protagonists who face extraordinary circumstances, as seen in both Princess Resurrection and his subsequent works like Time Stop Hero and Stella Must Die. His work has been published in English by several companies, including Del Rey Manga, Kodansha USA, and Seven Seas Entertainment, cementing his status as a recognized creator in the international manga market.