Line Joining Two Opposite Corners of a Square
This page is the CodyCross answer for the clue below from Welcome to Japan, Group 579, Puzzle 2 (Anime and Manga).
Question is: Line Joining Two Opposite Corners of a Square
and the answer is: DIAGONAL
Word Meaning:
DIAGONAL — (geometry) Joining two nonadjacent vertices (of a polygon or polyhedron).
Definitions from Wiktionary.