"Backward Rear" (for Sho-Gi Wife)

Tokione Starhouse Teacher's Lounge (4F)
Tokione Starhouse Theater 1 (2F)
Tokione Center Isle (B1)
Tokione Moon Forest Room 208

"Gooey Bed" (for Word Box)

Tokione Starhouse Elevators (3F)

"Unceasing Child" (for Wallpaper 2)

Tokione Starhouse Boy's Dorm (3F)

"Green Clouds" (for Smile Seed)

Lifeborn Farm (1F)
Lifeborn Aquaria Room (1F)

"The Right Lefthand" (for Wildgrass)

Lifeborn Residence B42
Lifeborn Licensing Center back office (3F)

"Worn out Mask" (for Staker 1)

Artiela Cemetery
Artiela licensing Center (2F)
Artiela TV Tower Employee Dorm I (22F)

"Transparent Mask" (for Baby World Elephant)

Artiela Concert Hall Dressing Room

"Tortoise's Full Speed" (for Electric Bulb for Jingle)

Shine Co. Office area (9F), in second office room if you go left comming out of the elevator.

"Folclore Senility" (for World Turtle)

Sanctuary, outside, in front of cathedral, on fence in middle area

"Muddy Water Gun" (for World Snake)

Paradiso, behind the ramp going to the roof
Paradiso, on the outside of cottage 3

"Warm hot Spring" (for World Elephant)

Paradiso, behind a tree
Paradiso, in bungalow 4
Paradiso, in cottage 3
Paradiso, on the outside of your house
Paradiso, in the cafeteria
Paradiso, Skypod boarding gate
Paradiso, unknown

"Wrinkling Cream" (for Sho-Gi Unicorn)

Sanctuary Skypod Entrance (behind a chair)
Sanctuary Cathedral Entrance
Sanctuary Cathedral Meditation Room

"Troubled Tangerine" (one for Wildgrass, two for Diamond)

Intelligent Sea Server room (training room)

Unknown

Wallpapers - The following is a list of how to the wallpapers:

Wallpaper 2: Collect and trade the "Unceasing Child" secret code.
Wallpaper 3: Inside a container in the Matia Mine
Wallpaper 4: Successfully complete Detective Mission 3.
Wallpaper 5: Inside a container in the first level of the Wilderness Ruins
Wallpaper 6: Tyrant Treasure I
Wallpaper 7: Awarded at the Artiela Museum with Art Coordinator license
Wallpaper 8: Suck all garbage (40) in first sweeper mission at Artiela Cafe.
Wallpaper 9: Successfully complete Detective mission 1.
Wallpaper 10: Given by Kamaro after you give him the Shouprieme Flower

Artwork - The following is a list of how to get the artwork:

Sho-Gi

Spy: Inside a container in the Artila Wilderness Ruins.
Miser: Inside a container in the Miracle Plateau (Artila).
Samurai: Inside a container in the Rock Castle Sky Cave.
Dragon: Tokione B2 Security Storage
King: Given by a man in Lifeborn B51 after completing the Stacker art.
Wife: Collect the four "Backward rear" Secret Codes.
Unicorn: Collect the three "Wrinkling Cream" Secret Codes.

Stacker

Stacker 1: Collect all three "Backward Rear" Secret Codes.
Stacker 2: Given by Mac after you have Stacker 1 (if your friendship level is high enough)
Stacker 3: Inside a container in Pirate Valley.
Stacker 4: Inside a container in East Sea West Coast (after Anemos).
Stacker 5: Inside a container in Spirit Lake B1.

The World - Collect the secret code pieces for the Baby World Elephant, World Turtle, World Snake, and World Elephant.