Bindle is a character that appears within The Minish Cap and he can be found within the Happy Hearth Inn on the lower floor. Bindle gives Link advice about the Happy Heart Inn, indicating that you really get what you pay for when you stay at the place. However, he states that you really don't know until you try out each of the rooms.
Link is able to fuse Green Kinstones at various points in the game with Bindle. As it is a Green Kinstone fusion, it is not set to a specific treasure chest, but instead, one of the many possible treasure chests. There is one random Red Kinstone within the game that opens up a location in the Hyrule Castle Garden leading to a Piece of Heart, as well as a random Blue Kinstone that opens up a tree in North Hyrule Field leading to a Fairy Fountain. Bindle is one of the many characters in which Link can make this Kinstone fusion with.