Zatoichi with his 26 films and over a hundred episode TV series starred by Shintaro Katsu is a well known franchiseTVTropes Warning as well as a meme as the epitome of the perfect blind swordsman. There's also the Film with Takeshi Kitano as Zatoichi and 3 more reboots, but let's forget those.
Now, Zatoichi is blind as a bat. So to make him in 4th edition, he needs to take blind, to fit the basic premise. Blind is pretty bad in itself, but a necessary stepstone. Then, he's also depicted as being a blind wandering barber, so he has to be clanless, which means he has to be built using one of the clanless variants of the ronin rulesL5R Core Rules 4th ed. p.234. In other words: he can't be a Samurai, he can't learn in non-shady Samurai schools.
What Insight Rank and School Rank combination our blind ronin needs to go blind master swordsman and reliably mitigate his blindness in combat with easy enemies and get on-par with more widely skilled samurai of roughly equal School Rank while retaining a social rank of between -1.0 (Entertainer) to 0.4 (Ashigaru)?
##References
References
BLIND [PHYSICAL] (6 POINTS)
###BLIND [PHYSICAL] (6 POINTS) YouYou possess no natural eyesight whatsoever save for a slight ability to determine light and dark. You suffer a penalty of -3k3 to all ranged attack rolls and -1k1 to melee attack rolls. Your base Armor TN is equal to your Refl exes Trait plus 5 (armor adds bonuses as normal). Your Water Ring is considered two ranks lower for the purposes of determining how far you may move as part of a Move Action. Any attempt at a Simple Move Action requires an Athletics/Agility roll (TN 20) or you are knocked Prone. You may not make Perception rolls unless the GM judges that you can use senses other than sight for the roll.L5R Core Rules 4th ed. p.156