I quite love how despite his tough exterior and rightousness, Kojûrô gets quite emotionnal a number of times throughout the games, anime and comics anthologies
Whereas Masamune, for all his cockyness and unhinged behavior, is more closed off when it comes to sentiments ; he's kind of on a "annoyed/excited" spectrum constantly
It tells a lot on what they are as character ; Kojûrô has a strong set of values, and he's emotionnaly invested in them, he's harder on himself than he is on other, and he took it as a personnal mission to guide Masamune to be the best version of himself - as such, his emotions are deeply tied to his sense of responsability
Masamune appear as a more cynical character overall, and I believe it's bc his moral code is less conventionnal and not something he feels the need to share ; he takes pride in his accomplishments, his reputation, and as such it makes sense that his priority is to look confident and cool
His sense of responsability expresses differently than Kojûrô, it expresses in maintaining a charismatic presence bc it's what gives confidence to his men and it's what gives his dream legitimity
It's why Kojûrô's role as a moral compass is so important, bc Masamune can and will lose sight of his surroundings bc he's more inherently self centered ; that's his weakness, but it's also the source of his strengh, the reason why he won't go down without a fight and won't abide by what's conventionnal
I think it's the core of the future he wants from Japan - and why Kojûrô follows him despite his flaws (Kojûrô is also deeply an unconventionnal individual, in my opinion, one that will ignore hierarchy if needed and one that has an incredible potential for violence)
((Ofc I'm not saying I agree with them haha I love both of their characters and the way they interact with each other ; but I still don't believe in a military gouvernement or anything with a centralized/vertical power system))
