This decision was based on Noriyasu and Tadakata both being "open country and commerce wing," as well as the fact that Noriyasu and Naosuke were on good terms with each other and exchanged personal letters.
乗全、忠固はともに開国・通商派であり、また乗全と直弼は個人的に書簡をやり取りするほど親しかったからである。