Kokiri Sword

The Kokiri Sword is the default sword Link possesses in both Ocarina of Time and Majora's Mask. It is also the weakest sword in both games.

Ocarina of Time
In Ocarina of Time, Link must obtain the Kokiri Sword before Mido allows him to visit the Great Deku Tree. The young hero can find the Kokiri Sword hidden away in a chest inside the Hole of "Z" in the Forest Training Center. This is the only sword Link can wield as a child, and when he is an adult, he uses the Master Sword instead.

Majora's Mask
The Kokiri Sword is equipped by default at the beginning of Majora's Mask, and is the same Kokiri blade which Link used in Ocarina of Time. It is hindered both by a short range and a lack of power, but can be upgraded to the temporary Razor Sword and then upgrade again into the permanent Gilded Sword by taking it to the Mountain Smithy in Mountain Village. Although Link begins the game with the Kokiri Sword, he is unable to use it when he is first transformed into a Deku Scrub by the Skull Kid.

Interestingly, the hilt and guard of the Kokiri Sword changed from Ocarina of Time to Majora's Mask.

Ocarina of Time Manga
In the, Link receives the Kokiri Sword from Mido after they defeat Gohma. It is also used to carve a Deku Shield out of the Great Deku Tree's wood.

Trivia
The Kokiri Sword appears in its Ocarina of Time incarnation as the blade wielded by Young Link in Super Smash Bros. Melee.