A bilingual handout may need one vertical Japanese passage beside a horizontal English explanation. Start by deciding which content should change direction. Rotating the design of an entire document to solve one panel can create unnecessary work elsewhere.

Make a working copy and identify the panel, its heading and any short numeric label. Keep the Japanese text available as editable text so a language reviewer can correct it. A picture of the words would make later wording changes harder to manage.

Pages requires Chinese, Japanese or Korean document formatting, or at least one of those languages in the Mac’s preferred-language list, for vertical text. To affect a text box or shape only, Control-click it and choose Turn On Vertical Text. Turn Off Vertical Text reverses that object’s direction.

The Document sidebar’s Vertical Text setting changes existing body text and makes new objects vertical. Apple also warns that enabling vertical body text changes inline tables into floating objects, even if vertical text is later disabled. Use the object control when only one panel needs the change.

Review the reading path inside the panel

Vertical text runs from top to bottom, with following lines to the left. For a short Latin group, select two to four characters, open the advanced options in Format, Text, and choose Rotate to Horizontal. This allows a compact group to be read left to right within the vertical passage.

Use a representative panel that contains punctuation and a short number, rather than testing only a single character. Read it from its intended starting corner and confirm that the relationship to the English explanation remains obvious.

Ask a reader familiar with the language to review the wording and reading order. A layout control can arrange characters, but it cannot confirm that a translation, name or punctuation choice is appropriate. Keep those editorial decisions separate from the direction setting.

Check the surrounding horizontal labels after resizing the panel. Ensure no label seems to belong to the wrong passage and no ending disappears beyond the available space. Then inspect the intended delivery copy at normal size. If it will be edited in another environment, verify that environment with this sample before constructing the full document.

Reference: Apple: vertical text in Pages.