In a medieval-like world where a destructive curse spreads by touch and turns people into black, skull-faced monsters called "Outsiders," the "inside" inhabited by people is shrinking every year. Merciless purges of people who are suspected to have been in contact by Outsiders are performed by the soldiers in service of the king, and their bodies are abandoned to the "outside." Shiva, a six-year old girl, has been abandoned in the outside woods by an old woman she calls her "auntie." She is found by an Outsider who she starts to call "Teacher."

Teacher has been living in an abandoned house near an abandoned village for some years, and is different and more humanlike than the other Outsiders, even though he doesn't sleep or eat. The two start living as a makeshift family. However, Teacher can't recall his own past, and can't bring himself to tell Shiva – who every day cheerily waits for her auntie to come get her back – that she has been abandoned. The two can also never touch, as Teacher is afraid he'll spread the curse to Shiva.

There are also other Outsiders lurking in the forests who are interested in Shiva, call her "a soul" and would like to take her to their "mother" at the bottom of a lake. They are very different from Teacher, and make Teacher question everything he knows about the world. At the same time, soldiers from the inside are also looking for Shiva for some reason.

Teacher (せんせ, Sense) Voiced by: Jun Fukuyama (Japanese); Gary Furlong (English) Shiva (シーヴァ, Shīva) Voiced by: Rie Takahashi (Japanese); Sarah Wiedenheft (English)

The Girl from the Other Side: Siúil, a Rún won the "Shōnen Tournament 2017" by the editorial staff of the French website manga-news. It was ranked 20th at the third Next Manga Awards in the print category. It was nominated for the Best Comic award at the 45th Angoulême International Comics Festival in 2018. The first volume was included on the list of Great Graphic Novels for Teens selected by the American Library Association's YALSA division in 2018; the third, fourth, and fifth volumes were included on the same list in 2019.
The feature-length film was nominated for the Feature Films Competition at the 9th New Chitose International Animation Film Festival in 2022. Additionally, the short-length film competed in the Films/Videos Made for Young Audiences category of the Ottawa International Animation Festival's digital event in 2020.