101Leafy researched the games.
Iron Katana

Made with technology from the Orient. A strong Sword, but requires maintenance.
| Class | Long Sword |
|---|---|
| Rarity | 1 |
| Attack | 480 |
| Slots | 0 |
| Price | 1,400z |
Upgrades
| Upgraded from | Buster Sword+ |
|---|---|
| Upgrades into | Iron Katana "Grace" |
Can also be made new at the smithy.
Upgrade tree from モンスターハンターポータブル 2nd G 公式ガイドブック (Enterbrain, 2008), page 692.
Materials
Machalite Ore ×3, Iron Ore ×8, Carpenterbug ×8, Ice Crystal ×8
Hard Ticket ×1, Iron Ore ×1