When you exit the gate between Route 5 and Nimbasa, Bianca stops you, gives you HM 02: Fly, and teaches you about Hidden Grottos. These are small passageways through trees indicate by darker green leaves between two trees. You interact with them, and you will be asked if you would like to enter. The contents range from Pokémon with their Hidden Abilities, items, or nothing at all. Inside this Hidden Grotto, however, is a Minccino. It is guaranteed to be there (and it is actually really rare to get otherwise), so catch this one. It has its Hidden Ability, Skill Link, After that, the Hidden Grotto will be random as to the contents inside.
Also on this route is a trailer with a maid inside. This maid says that she is cooking something and needs ingredients. This is what is known as an Item Maniac. These people will buy your items from you for a higher price than what you would sell for in a regular Poké Mart. Tiny Mushrooms and Big Mushrooms are the items of interest here, but later there will be another item that can be sold for good money. Keep this woman in mind when you pick up a mushroom or a berry you don't know what to do with.
Also on this route is a Pokémon Breeder who is selling five EV-Decreasing berries for 200 dollars.
Previously, you could not get past this route because of a Biker by the name of Charles blocking the path with a unique type of battle style that everyone was watching. Now, you can actually face Charles and have him move so you may proceed. In Black 2, this type of battle is a Rotation Battle, but in White 2, it is a Triple Battle.
After defeating him, he moves so you may advance, but there is a hidden Hyper Potion on the road by the dancer that can be picked up. Another Hyper Potion can be found at the beginning of the route, but instead of going on the pavement, go down below the bottom fence line and follow it to a Poké Ball containing said Hyper Potion.