Reppumaru (烈風丸, "Reppu" meaning Gale and "Maru" is a common suffix for Japanese male names) is a sword that Sakamoto Mio forged while driving her magic power into it, this is the Fuso sword that she employed throughout the second season of Strike Witches. A bewitched sword that drains its user magical power, Miyafuji Yoshika almost fainted from magic loss when attempting to draw it once.
Prepared as a countermeasure against the decrease of her Witch abilities caused by age, Reppumaru posseses the power to cut up a Neuroi's beam and its body. Having lost the capacity to generate a magic shield strong enough for the actual battles, Mio also employed the Reppumaru defensively as a satisfactory replacement. A masterpiece that Mio is proud of. However, the result of obtaining the power to fight even while her magic power continued to decay was that Mio's lifespan as a Witch was drastically cut short.
The name of the technique performed with this sword is Reppuzan.
During the decisive battle against the Super-Hive in Venezia, Yoshika used it to destroy the Hive's giant core at the cost of all her magic power. Afterwards, it fell on the sea and was last seen washed up on some beach, along with the J7W1 "Shinden" Striker.