Divine Instruments can be optained through defeating bosses and buying them from merchants. Some even grant elemental powers whenever Amaterasu needs it. Two Divine Instruments can be equipped at a time, one as a main weapon and another as a sub. Each weapon acts differently depending on what it's set to. When Amaterasu and Chibiterasu run out of ink, their Divine Instruments also disappear.
When you start a New Game + all weapons will be brought forward to the new file except the final tier weapons.
 The Reflector
The ancient mirror treasure was used, not as a mirror in the modern sense, but as a ceremonial object. We tried out a lot of different ideas when we were in the design testing phase, but because the mirror on Amaterasu's back balances well with the character and helps to really bring home the point that Amaterasu is a sun god, we decided to make it the basic weapon that the player first encounters. The reflector weapons carry a good balance of speed and power, making them the easiest to use. They also work well as a sub weapon since they can be used for defense unlike the other weapon classes. If the player successfully defends against an enemy attack using the sub weapon, then it can open up some enemies for a throw. Throwing an enemy can cause a lot of damage. In addition, if the block is timed just right, it can restore some of Amaterasu's health. Also if used to defend at the right time Amaterasu will use a smash attack which will give out Demon Fangs.
Although the ability to defend is well suited for beginners, it can also be useful for experts who master the technique thanks to the power of the throw feature. By learning the "Wailing Mirror" technique at the Dojo, Amaterasu's health can be restored by blocking even if the timing is not just right. This is the weapon to have for players interested in a more defensive style.
There are five reflectors availible in the game and they get stronger as you go up the line:
 The Rosary
The necklace treasure is a symbol of life. It is said that the beads represent the life force inherent in the womb. The rosaries act as the long-range weapon in Okami. As primary weapons they act as a whip and as sub weapons they act as bullets being fired. Rosaries are the weakest of the three weapon classes, but they are perfect for players who want to keep their enemies at a distance. Rosarys also have no recharging time between use so you can keep firing combo after combo. This also makes it the best generator of Godhood. Different rosaries equipped as sub weapons produce different bullet effects, so we recommend trying them all out. It's also possible to further increase the firing speed by learning the "Bead String" technique at the Dojo, resulting in some rapid-fire action.
Like reflectors, there are five Rosary's availible in the game and they get stronger as you progress in the game. These Rosarys are:
 The Glaive
The sword treasure is a symbol of power. You obtain your first Glaive considerably later in the game compared to other weapons. Among the different Divine Instrument weapons, the sword is the only one capable of a charged attack for dealing more damage. Of all the weapons, it is the slowest to wield, but it makes up for speed with power. For players who are confident that they can land their blows, this is definitely the weapon for them. The glaive class of weapons packs a punch equipped as the main or as the sub weapon and is suited for battles focusing on dealing heavy damage to the enemy. There are two levels of charged attacks depending on how long the weapon is charged. After learning the "Sword Dance" at the Dojo, the amount of time it takes to charge up an attack is cut in half allowing for quick and devastating attacks in battle.
When used as a sub attack, Amaterasu will jump into the air and sail into her enemy upon the glaive. This move too has to be charged.
Once again there are five types of Glaives and they grow in strenght when you progress up the line. The Glaives are:
Chibiterasu has his own mini-version of the Reflector Divine Retribution as well as Tsumugari and the Devout Beads. However these weapons cannot be bought or obtained quite like in Okami. His first Rosary will be found in Sei'an City and his first Glaive will be found in the 5-Story Pagoda. Then each of his Weapons can be upgraded twice by the Blacksmith in Yakushi Village. The Blacksmith will move in once he convinces a person to migrate to the village. Lucky Coins must be given to the Blacksmith in order for him to offer the upgrades. Only five Lucky Coins are needed in total although there is much more to be found. Demon Parts are then required by the Blacksmith in order for the Weapon to be forged.
Chibiterasu's partners also have their own weapons which the player can use to attack enemies. Kuni uses a wooden sword like his Father, Nanami uses a small blue sword, Kagu uses a whip made of cherry blossom petals and Kurow uses his flute to create damaging musical notes.
Divine Retribution - Initial Reflector.
Purity Reflector - Unlocked after two Lucky Coins and available for upgrade in exchange for ten Demon Bones.
Truth Mirror - Unlocked after five Lucky Coins and available for upgrade in exchange for ten Demon Skins and ten Demon Livers.
Devout Beads - Initial Rosary that is acquired in Sei'an City.
Sun Beads - Unlocked after two Lucky Coins and available for upgrade in exchange for fifteen Demon Bones and ten Demon Skins.
Mystic Beads - Unlocked after five Lucky Coins and available for upgrade in exchange for fifteen Demon Skins and ten Demon Livers.
Tsumugari - Initial Glaive that is acquired in the 5-Story Pagoda.
Light Sword - Unlocked after two Lucky Coins and available for upgrade in exchange for fifteen Demon Bones and five Demon Skins.
Feather Sword - Unlocked after two Lucky Coins and available for upgrade in exchange for five Demon Skins and twenty Demon Livers.
This Weapon is exclusive to Okamiden and will be unlocked after the game is completed once. They are similar to Dark Chibiterasu's used at the end of the game. They are two crystals that sit on Chibiterasu's shoulders and can be fired. Although they can not be upgraded and they attack slower, their range and power are far greater than the other Weapons. They utilise the elements of fire, ice and water all at once.
 Based on
The weapons choices in Okami are based off the three legendary treasures of the Japanese Imperial Regalia.
The Reflector is based off the Yata-no-Yagami, which is a hand mirror that was said to be created to lure the God Amaterasu out of her cave. Upon catching her reflection, Amaterasu was so in awe that the other Gods were able to pull her out of the cave.
The Rosary is based on the Yasakani-no-Magatama which was also placed outside of Amaterasu's cave in an attempt to lure her out. The Yasakani-no-Magatama is actually a curved jewel rather than a string of beads however it is in the shape of the beads that the Rosaries are comprised of. Susano's pendant is also shaped like the Yasakani-no-Magatama.
Finally, the Glaive is based on the Kusanagi-no-Tsurugi, which was the sword Susano-o pulled out of the Orochi and presented to Amaterasu as an apology.
- Unlike Amaterasu, Chibiterasu can use his Weapons outside of Demon Scrolls, although they disappear in cut scenes.
- Concept art for Glaives shows Amaterasu sprouting arms from her back to wield it.
- The picture on the background of the fan menu shows Amaterasu's currently equipped Weapon.