Oftentimes Genji was envious of his older brother and how he seemed to attain everything that was desired of them. They might have competed on equal level in martial arts, which ever they picked, but fighting skills were not the only thing asked of a Shimada man; there was their family history rich with legends to live up to, and endless lectures of the very narrow path in shadows they had to walk. They were to be absolutely loyal to the clan, to choose honor and obligation over human desires and temptations, and to carry on the clan's tradition the same way their ancestors had done for centuries. They were links in a chain, parts of something greater than themselves and they were to do everything in their power to carry that on with pride and honor.
To Hanzo this seemed to come effortlessly, to Genji not so much.
Maybe Shimada blood ran thin in Genji's veins, or maybe he had been spoiled too much as a baby like Hanzo claimed, but he struggled to fall in line. He knew he should have, he knew it was a great honor, but to be honest something being “a great honor” didn't really move Genji's opinion to one way or another. The way the rest of the men of his family spoke of it made honor sound like it was some sort of an enlightenment, something physical and real that had fallen over their shoulders from the high heavens, but Genji didn't feel any of it. He had no idea what it was that his brother felt to make him this driven and disciplined, and all Genji was left with was mimicking him.
Genji did rather what his own living beating heart wanted instead of what his long dead ancestors would have probably approved of, and to him this seemed much more sensible than worshiping ashes. The clan elders, Father and his only brother might have all disapproved of this, but Genji knew how to walk the fine line between testing the clan's patience and throwing traditions to their faces. Genji knew he was smart and he knew how to make amends, and though he begrudgingly admitted that a no small part of that wisdom was due to their family business and Father's teachings, he shamelessly used those skills for his own ends even if it might have made a little bit of a hypocrite out of him.
Walking the fine lines of social relations and making amends was a precious talent though, and Genji took great pride in how it evened the scales between him and his perfect older brother, because if there was one thing Hanzo was completely inept in it was the fine art of social relations. If there indeed was some cosmic scale of honor Genji knew he was raking up points against his brother solely by keeping him out of useless arguments and balancing out his stupid plunders before they escalated into a full-blown fight that would result in some people losing head and fingers. Somehow Genji felt that Hanzo had been born into the wrong century and that he would have done much better back in the time of civil wars or as a ruthless conqueror because he was just as unable to learn the way of bar chatter and just enough banter with the rival clan members as Genji was feeling the blessed cloak of honor and duty.
But Genji couldn't always be there by Hanzo's side to filter out his blunt words and too honest comments, especially when his older brother chose to drink. Despite his proper and disciplined ways in every other moment of his life, Hanzo was a mean drunk. The more he drank the more irritated and rowdy he got, and as it would happen the series of very uncomfortable and nasty events involving some very compromising information was sparked because Hanzo drank a bottle of sake and decided to open his mouth.