Boundaries

Boundaries are the seas that connect the Near Shore with the Far Shore, and they can be accessed in various ways.

They were introduced in Chapter 4, when Kou described his older brother telling him about these boundaries that connect both shores.

There is a stretch of water running between deserted buildings and telephone poles, and the sun can be seen descending in the horizon. Kou also mentions how forgotten objects such as used dolls, broken television boxes, and other vintage articles are discarded and have drifted to piles.

Locations
There are several spaces in Kamome Gakuen where one can access the boundaries: Most of the School Wonders' boundaries contain water, with the exception of Tsuchigomori's boundary. At the end of Chapter 40, Tsukasa also reveals Shijima hiding under the tablecloth as water can be seen under her feet in the broadcasting club's room.
 * No.2 The Misaki Stairs
 * No.3 Hell of Mirrors
 * No.4 Shijima-san of the Art Room
 * No.5 The 4PM Bookstacks
 * No.6 Shinigami-sama