Game 1 is characterized by the use of items mainly from the Paper Mario
series, but also from related games, Pokémon, Fire Emblem, BlueKara's
Buzzy comics, and the real world. The merchandise available in the game's stores
The Ninja Club Shop will only sell to people who have won belts from the Dojo; there is a different section for each belt. Its merchandise is supposed to be kept secret, but Game 1 will probably never continue.
Note: Apparently, I got Toad Town's two main stores mixed up: the smaller, more expensive store is called the Shroom Grocery, while the one accessible later in the game is Harry's Shop. I have left this mistake in, however, because it seems more sensible to me that the smaller and pricier one would be an independent shop and the bigger, more competitive one a supermarket. Plus, it was already played out in the game :P