Easy modeToggle Jubei Alternate's Sunglasses:
When using him, press L2.
Green Realm Item:
Use the green wedge on the green portal found in a building near the water bridge areas. You will get the Red Necklace.
Get the Mystery Item:
Go to the Dark Realm, fight the 20 levels and on the last level there will be a firery crack in the ground. Examine twice, enter the light and then open the chest.
Purple Realm Item:
Use the purple wedge on the on the purple portal at the top of Gifu castle. You will get the Fire Sword.