Resource pack that adds 5 models of different katana.
OptiFine or CIT Resewn is required.

Rename any sword on the anvil.

minecraft:wooden_sword -> Wooden Katana
minecraft:stone_sword -> Stone Katana
minecraft:iron_sword -> Iron Katana
minecraft:golden_sword -> Golden Katana
minecraft:diamond_sword -> Diamond Katana
minecraft:netherite_sword -> Netherite Katana

Preview

For OptiFine:

Video Settings > Quality > Custom Items: ON

For CIT Resewn (Mod Menu):

Mods > CIT Resewn > Configure > Enabled: Yes

Tested versions:

1.19.x (CIT Resewn)
1.18.x (OptiFine)
1.17.x (OptiFine)