|Other||Twinsword (双刀, Sōtō)|
|Manga||Volume #49, Chapter #454|
|Anime||Naruto Shippūden Episode #199|
|Game||Naruto Shippūden 3D: The New Era|
|Appears in||Anime, Manga, Game|
According to Suigetsu, this is the only sword still in Kirigakure's possession out of the original seven blades, by the time of the Fourth Shinobi World War. Suigetsu also noted that his brother Mangetsu mastered the use of this sword in the past and is most likely its former wielder.
The weapon features a wide, flat blade with two curved indentations near its base, creating a sort of cross-guard. Two handles are connected to one another by a short length of cord, earning it the title of "twinsword" (双刀, sōtō). The overall sword looks like a flounder fish in shape and is also apparently very heavy, as Chōjūrō tires easily when carrying it for extended periods of time. When unleashed, it emits chakra from the holes found at the top which coats the entire blade.
The sword is capable of storing chakra and the two holes at the tip of the blade emit it on command. This can then be formed into various weapons, including a hammer or a longer sword. The size of the resulting weapon appears to depend upon the amount of chakra stored up beforehand, meaning a larger quantity will be met with a similar increase in the weapon's ultimate size. These weapons are also formed with notable speed.
- Both hirame and karei are Japanese names for species of flounders. The flounders with their eyes on the left side of their body are called hirame (鮃, 平目, 比目魚), while those with their eyes on the right side are called karei (鰈). Befitting its name, Hiramekarei is shaped like these fish.
- Hirame can also come from hirameku (閃く, "to flash", or "to flicker"). Karei can also mean splendour (華麗).
- Mangetsu Hōzuki is the presumed owner of this sword during the time of the previous generation of Seven Swordsmen, as he was one of two not seen with a sword like the other members, when they were reincarnated by Kabuto Yakushi. Given that Fuguki Suikazan was the previous owner of Samehada and his sword is currently in the possession of Killer B, only Hiramekarei remained unclaimed.
- This is the only one of the seven swords not to have a direct kanji translation, due to its name being written in katakana.