Go to the Minister of Autumn in the "Make Your Own Fairy" part of the game. Unlock the listed bonus by entering the corresponding codes:

BONUS - CODE
For Animal Fairies:
Aster top, Aster skirt, Aster headband, Aster boots - 7535-6578-0054
For Garden Fairies:
Dahlia top, Dahlia skirt, Dahlia headband, Dahlia slippers - 9371-1418-1583
For Garden Fairies:
Pansy headband - 4381-9426-6582
For Garden Fairies:
Pansy skirt - 1823-6488-0698
For Garden Fairies:
Pansy slippers - 7939-2022-0172
For Garden Fairies:
Pansy top - 0003-5285-1616
For Light Fairies:
Lantana top, Lantana skirt, Lantana headband, Lantana slippers - 3328-4360-6775
For Light Fairies:
Marigold headband - 1264-3468-9475
For Light Fairies:
Marigold skirt - 5083-3737-9968
For Light Fairies:
Marigold slippers - 5904-5237-0564
For Light Fairies:
Marigold top - 4764-3013-6282
For Tinker Fairies:
Euphorbia top, Euphorbia skirt, Euphorbia headband, Euphorbia boots - 8196-3691-3101
For Tinker Fairies:
Poinsettia top, Poinsettia skirt, Poinsettia headband, Poinsettia boots - 7891-5940-5474
For Water Fairies:
Curcuma top, Curcuma skirt, Curcuma headband, Curcuma slippers - 9662-7452-5024
For Water Fairies:
Tillandsia headband - 6904-4575-3307
For Water Fairies:
Tillandsia skirt - 0384-6266-1444
For Water Fairies:
Tillandsia slippers - 9288-6449-1545
For Water Fairies:
Tillandsia top - 3133-6138-0316
Flower Seed (ten time use) - 1445-5275-2863
Nut (ten time use) - 2793-9162-0449
Pumpkin (ten time use) - 3010-8766-0864
Round Leaf (ten time use) - 7512-4530-8252
Silkworm Thread (ten time use) - 2495-6208-7251
Spider Silk (ten time use) - 0431-0738-6429
Twig (ten time use) - 9051-9214-2887
Fairies DS Kit in DGamer - 7163-9136-7487
Sceptre DS Stylus in DGamer - 7451-8050-0684
Tink DS Case in DGamer - 2942-4327-6109

Unlock the following Dgamer items by performing the corresponding tasks:

ITEM - HOW TO UNLOCK
Fawn outfit - Complete Fairy mode with an Animal fairy.
Iridessa outfit - Complete Fairy mode with a Light fairy.
Rosetta outfit - Complete Fairy mode with a Garden fairy.
Silvermist outfit - Complete Fairy mode with a Water fairy.
Tinker Hammer - Complete Fairy mode with a Tinker fairy.

ACHIEVEMENT - HOW TO UNLOCK
Animal Fairy: Complete Fairy mode with an Animal fairy.
Garden Fairy: Complete Fairy mode with a Garden fairy.
Light Fairy: Complete Fairy mode with a Light fairy.
Tinker Fairy: Complete Fairy mode with a Tinker fairy.
Water Fairy: Complete Fairy mode with a Waterl fairy.