Japanese writing paper (lined with a square grid, one square per character); manuscript paper
原稿用紙に丁寧に文字を書き込んだ。
I carefully wrote characters on the manuscript paper.
先生は作文を原稿用紙三枚で書くよう指示した。
The teacher instructed us to write the essay on three sheets of manuscript paper.
最近は原稿用紙を使う機会が減っている。
Opportunities to use manuscript paper have been decreasing recently.