Swords that were often used in battle and fight a lot against enemies, will lose durability and start rusting. In the Polishing (研磨) area you can repair your damaged swords. Polishing needs time and resources. The amount of time and required resources, depends on how much your sword is damaged (see Sword Rusting ) as well as their level.
When a sword girl is in repair, you cannot use her in battle or for work until the repair process is completed. You can skip repairs by using Repair Tokens.
At the beginning, a player owns one Repair Slot, but can unlock another one after a few days. More Repair Slots can also be bought in the Shop .
In each slot you can repair multiple swords (up to Five), but only if you unlocked more space. You can do that by increasing the level of your mansion (see Residential Area ).