The official Splatoon Tumblr has been updated with a few more details regarding equipment in the game. It also shares the localized English names for the various store owners that will sell you equipment to customize your character with.
squid jellyfish that owns the clothing store is named Jelonzo, the lady that owns the headgear store is Annie, and the… fried shrimp… that owns the shoe store is named Crusty Sean. All three characters value “coolness” and will only sell you certain items if your “coolness” is high enough.
You can participate in battles to earn experience and raise your rank. This rank is the yardstick by which your coolness is measured. If you aren’t cool enough, the store owners will deny you certain items.
Splatoon will be released this May for Wii U.