Wayfinder

"Somewhere out there, there's this tree with star-shaped fruit. And the fruit represents an unbreakable connection. So as long as you and your friends carry good luck charms shaped like it, nothing can ever drive you apart. You will always find your way back to each other. An unbreakable connection"

- Aqua, explaining the Wayfinders' effect and appearance.

A Wayfinder (つながりのお守り Tsunagari no Omamori) is a star-shaped lucky charm that is used to provide luck to travelers. It is usually woven from Thalassa Shells, with some token at the middle, but there have been several imitations made from other materials throughout the series. It is designed after the Paopu Fruit, which is said to tie friends together. In Kingdom Hearts Birth by Sleep, the bond that the charms represent is manifested physically as the Dimension Link system.

Due to their special significant to relationships, Wayfinders are used as the Keychain token for the Oathkeeper, the Brightcrest, and the Kingdom Hearts Birth by Sleep version of the Ultima Weapon, and are also part of the base design of that Ultima Weapon.

Design
All Wayfinders are shaped like five-pointed stars and are usually from Thalassa shells stitched together with a token in the center.

Kairi's Wayfinder is made of Thalassa shells that are pale yellow toward the center and pale pink toward the tips. The shells are held together by grey, X-shaped stitches. The token in the center is a brown crown somewhat similar to the one on Sora's necklace. Kairi sketched a simple, brown drawing of Sora's face on the topmost shell on the charm and a chain is attached to the tip of this shell. Naminé transformed Kairi's Wayfinder so that it resembled a simple, yellow star while Sora was in Castle Oblivion, but later changed it back.

Aqua's, Ventus's, and Terra's Wayfinders are made from stained glass with silver frames, and have brown stitches and a brown cord tied to the topmost shell, and the token is the Mark of Mastery symbol. Because Aqua did not have access to actual Thalassa shells, the charms are made from other materials. The token is silver on Aqua and Ven's Wayfinders, but gold on Terra's. Aqua's "Thalassa shells" are predominantly blue with cyan tips, Ven's are light green with sea green tips, and Terra's are orange with yellow tips.

Stitch constructed his own Wayfinder out of junk, with a glowing, light green star as the center token. The five pieces of the Wayfinder are held together by short rods, and no two pieces are alike. The largest is teardrop-shaped with a lower half that is sky blue with light purple "stitches", a salmon pink upper half, and light green circle in between the two halves. One piece resembles Stitch’s blaster and is yellow with some small red additives. One piece is roughly diamond shaped with a yellow and red tip and a sky blue base. The smallest piece is teardrop-shaped, salmon pink, and has a sea green "X" near its tip. The last piece is a misshapen oval with a sky blue upper half and a light purple lower half with "stitches" of the same color lining it.

Kingdom Hearts Birth by Sleep
Aqua creates three Wayfinders for Ventus, Terra, and herself, and presents them to the others the night before she and Terra take the Mark of Mastery exam, explaining the folklore behind the Paopu Fruit, and voicing her wish that they will always stay together. She jokingly apologizes for not being able to use the traditional Thalassa shells, and points out the Mark of Mastery emblem she had woven into the center, explaining that she had worked some magic on the charms to make up for their non-traditional composition. This spell is soon revealed to be the source of the heroes' Dimension Link ability.

In Deep Space, Stitch sees Terra's Wayfinder and builds a replica out of space junk, in order to demonstrate his understanding of friendship. Unfortunately, his Wayfinder is destroyed when he is attacked by Gantu. Some time after the final battle at Keyblade Graveyard, Stitch escapes into space in a stolen spaceship, with a fully-repaired Wayfinder at his steering wheel.

Kingdom Hearts
As Sora and Riku gather provisions for their raft, Kairi works on a Wayfinder to bring them luck. However, the destruction of Destiny Islands prevents them from ever testing it out.

Much later on, after Sora rescues Kairi from Hollow Bastion, she gives him the finished Wayfinder—now sporting a drawing of Sora's face as its token—for luck and makes him promise to return it to her after he gets things fixed, which he agrees to. The powerful bond between Sora and Kairi that the Wayfinder represents gives it the power to act as a Keychain token for Sora's Keyblade, transforming it into the Oathkeeper. As Sora and his friends enter theEnd of the World, he looks at the Wayfinder again, and thinks about his promise to Kairi.

Kingdom Hearts: Chain of Memories
As part of Marluxia's plot to brainwash Sora, he has Naminé alter Sora's memories, causing him to see Kairi's Wayfinder as a simple golden star charm that he "received from Naminé." Naminé also gives the World Card for Destiny Islands to the Riku Replica, in the form of Sora's altered charm, causing strife between Sora and the fake Riku as they fight over whose memories of Naminé and their supposed promise to her are real.

After Sora's penultimate battle with "Riku" on the eleventh floor of Castle Oblivion, the Replica drops his own charm, and it reverts into its card form, which Sora uses it on the next White Room. However, after defeating the Darkside within that fake world, Naminé reveals herself to Sora and urges him to remember the truth, causing him to recall Kairi's face, and transforming the Wayfinder back to its true form. After leaving the White Room, Sora finds Naminé and demands an explanation, and she tells him that the two have never actually met before. However, Sora is immediately attacked by the Riku Replica, who still believes he had made a promise to Naminé. After defeating the Riku Replica, Sora is then ambushed by Larxene, who steals Naminé's fake charm and taunts Sora with a threat to destroy it. Despite knowing that both the charm and his "friendship" with Naminé were fake, Sora defends them and defeats Larxene.

After Sora defeats Marluxia and gets into a Memory Pod in order to regain his memories, Naminé tells him to remember the "light in his darkness" in order to bring his lost memories to the surface. Searching for the memory, Sora looks at Kairi's Wayfinder, and soon remembers her name.

Kingdom Hearts II
In Roxas's dreams of Sora's memories, he sees Kairi threading the Wayfinder on the sands of Destiny Islands, leaving one lone Thalassa shell to be washed away by the waves.

After defeating Xemnas once and for all, and returning to Destiny Islands, Sora finally returns the Wayfinder to Kairi.

Blank Points
As Sora prepares to leave to save "those who are suffering," Kairi once again gives him her Wayfinder, telling him, "See you soon."

Kingdom Hearts: 358/2 Days
On Day 193, Xion has an vision of Kairi giving Sora her Wayfinder.