If swordsmith is everything he need in life, then why married, bringed a kid into the world and then treat them as something nuisance and wasted your time ? Not even because "I need a successor" because, maybe it's off the screen, but we doesn't seen him teaching his son how to make a sword at all ... that make me kind of wonder what happen with the "masterpiece" katana make him died from heart attack, maybe due to overjoice, it must gather dust in the shelf somewhere
At least Ryouma have his happiness now