Did I say Pikachu? Sorry, I meant Pikachus. Plural. This ad marks an upcoming Pikachu event in Yokohama. The name of the event is "Pikachu Tairyou Hassei Chuu" (ピカチュウ大量発生チュウ) or loosely, "Loads of Pikachus Springing Out".
The event kicks off on August 9 in Yokohama. Expect many Pikachus.