Game Boy Advance store:

First off, you need to have GameBoy Advance to get into this "secret" area of the game. After opening your file simply go into the Rennu Town in the past, and goto the Sword Target practice mini-game. The door that was once locked is now open. In this exclusive GBA shop everything cost a measley 100 rupees. There are only 3 things for sale, a Gasha seed, a GBA Advanced Life Ring, and magical ring