Kou just arrived in France, and was meeting Catherine, who is a kwōtā and had grown up in France, for the first time. Catherin spoke French in the first panel. Kou assumed - correctly - that Catherine would speak Japanese, and tried speaking Japanese to her in the second panel, but Catherine faked not understanding it in the third panel.
The reading order is: Right column top to bottom, then left column top to bottom.
Kou just arrived in France, and was meeting Catherine, who is a kwōtā and had grown up in France, for the first time. Catherin spoke French in the first panel. Kou assumed - correctly - that Catherine would speak Japanese, and tried speaking Japanese to her in the second panel, but Catherine faked not understanding it in the third panel.
The reading order is: Right column top to bottom, then left column top to bottom.