Koori no Jouheki (Book Version) | 氷の城壁 | Ice Castle Wall | Rompiendo el hielo | 얼음 성벽

The Ramparts of Ice (Japanese: 氷の城壁, Hepburn: Kōri no Jōheki) is a Japanese web manga series written and illustrated by Kōcha Agasawa [ja]. It was first published as a webtoon and was later serialized through Line's Line Manga digital service from January 2020 to April 2022. Shueisha published its chapters in 14 tankōbon volumes from July 2023 to February 2025. An anime television series adaptation produced by Studio Kai premiered in April 2026.

Socially awkward Hikawa Koyuki is used to keeping everyone at arm's length, choosing to spend her high school days entirely alone. Her solitary world is turned upside down by Amamiya Minato, a boy who seemingly ignores her emotional walls and constantly closes the distance between them. Soon, their orbit pulls in the wildly popular Miki and the easygoing basketball player Youta. Experience the sweet, awkward, and complicated dynamics of these four teenagers as they navigate their bumbling youth together in this charming original webtoon!