Ieyasu also felt anguish about how he could solve an ethical problem of destroying the Toyotomi family, his master family, asking Razan HAYASHI about right and wrong of To-O (Tang Wang)/Bu-O (Wu Wang) (Zhou Dynasty China) Hobatsu-ron (a theory in ancient China about expelling a disqualified prince).
また、家康は林羅山に湯王武王(周)放伐論の是非を問うなど、主家である豊臣家を討つことの倫理的な問題をどう解決すべきか苦悩している。