Donki

This is Aisaka's trusty sword. It is a large cleaver type sword that can change its size and length, allowing her to reach opponents further away or deal more devastating damage to those that she is attacking. The sword itself is capable of handling chakra flow, and can have its size manipulated by the user inputting more or less chakra. Since it is not a permanent container, once the chakra runs out, the sword will return to its original, but still dangerous, size. Its said to be distantly related to the Kubikiribocho, the sword her uncle used up until his death.