It described that Karahashi was violated by Nariaki when she was sent to him as the bearer of a letter from Yoshinobu, who had intended to avoid giving the letter political coloring as much as possible by entrusting it to Karahashi, who was apolitical person.
また、慶喜と斉昭との手紙のやりとりで政治臭を出来る限り消すために、政治とは無縁の唐橋を使いに出したところ、斉昭に手篭めにされた事になっている。