Kusakabe Seven Swords

The Kusakabe Seven Swords (草壁七剣 Kusakabe Shichi Ken) are the seven strongest swords of the Kusakabe clan. They were introduced by Misuzu Kusakabe as the Kusakabe Five Treasures (草壁五宝 Kusakabe Go Hou) at first but later in the story, Misao Kusakabe revealed that there were originally seven swords, and the Kusakabe merely ignored the existence of the two in Misao's possession as they thought it was a stain in the clan's history.

List of swords

 * Kogarasumaru Amakuni - a black katana that Misuzu used most often. It emits some sort of energy to strengthen the sword to a certain degree.
 * Kannagiri Nagamitsu - designed like a claspknife. Can extend the blade to surprise the enemy. It special trait is the extreme sharpness.
 * Kashagiri Hiromitsu - the largest of the swords. Uses demonic flames to increase offensive power.
 * Raikiri - a sword with the shape of a lightning bolt. It emits lightning and has great utility. Mainly used by Kakeru Satsuki.
 * Onikiri - the exact function is unknown, but appears to have the ability to curse the opponent's wound when hit. It was taken by Misao Kusakabe during her exile.
 * Kumokiri - the ability is unknown but in the anime, it appears to be of wind element. The weapon was taken by Misao Kusakabe during her exile..
 * Doujigiri Yasutsuna - also known as the cursed sword. This sword devours life energy of the wielder and turn that energy into great power.

Trivia

 * It is worth noting that according to Misao, the way these swords gain the powers and form they are now is very similar to Inuyasha's Tessaiga. These swords were said to have absorbed the blood of the demons they first slayed and thus gain the power of the demons. For example, Kogarasumaru was believed to have slain a giant crow and Raikiri had cut Raijin, while Doujigiri, as its name implies, was the sword that slayed Shutendouji, one of the three most powerful youkai of Japan who was believed to be the king of the Oni.
 * In the anime, Misuzu explains that duels were set for the strongest warriors to inherit the weapons, instead of families. There was an unspoken rule of only one sword per warrior. Misuzu earned all the swords legitimately, but was ostracized for her actions, including killing her father for Doujigiri. In other media, it was similar, though she didn't kill her father, but wounded him to a point where he couldn't use a sword again.
 * The powers of Misao's swords seemed to be reversed between the Manga and the Visual Novel while the anime doesn't address them.