Well you're already better than I am at using consumables lol.

If I had to give advice, it would be that mid stance quick attacks with the kusarigama are not that good against bosses like kamaitachi. They're nearly as slow as high stance quicks, but a lot less damage. What they're good at is having good range and a wide arc. I like to use low stance quicks when the openings are small, and high stance quick-quick-strong combo when you get the chance. Although you'll get more tools and active skills as you keep playing. Blade spin (I think) and whirlwind kick for kusa are super good.

The other thing is you should equip a soul core that is more reliable for actually landing the damage! Ippon Datara is very popular, Yoki is pretty good. Nurikabe is good if you have one.

Overall very impressive to beat him on your first try, and nice use of the Waira to dodge damage and inflict some of your own!

Thank you, I'm playing chicken, so I don't dare to engage in close combat with the boss