This table summarizes the number of text boxes for each character. In conclusion, Kusakabe has the fewest, making them the recommended choice for speedruns.

https://docs.google.com/spreadsheets/d/e/2PACX-1vQT2fzdQv59yoo_sZ4BdBNZw4iBzx1QzYbWAY7PN2-22uRRKCMqOlndvImDKoGWp7I8HtsQH7IeqzdU/pubhtml