\ 3 stores, one stamp each. /
3 official Pokémon stores in Chiba. Tap one for its address, floor and map, and stamp it when you visit.
Yes, and it hides behind a Tokyo name. Pokémon Center Tokyo-Bay is in Funabashi, Chiba, on the 2nd floor of the West Wing of LaLaport TOKYO-BAY, about 20 km from Tokyo Station as the crow flies. It opened in 2013, and Pikachu, Ampharos and Marill are on its logo. Minami-Funabashi Station on the JR Keiyo Line is about 5 minutes away on foot. From the south exit of Funabashi Keibajo Station (Keisei Line), allow 10 minutes. The official page also points to a Pokémon Card Station to combine with the visit.
Chiba has two smaller Pokémon Stores as well:
Chiba's four Poké Lids are all in Sawara, the old town of Katori. That is 51 km from Tokyo-Bay, but only 17 to 22 km from Narita Airport. They show Galarian Farfetch'd, Rookidee with Falinks, Lotad with Seedot and Staravia, and Florges with Fletchling. A long Narita layover is the easiest way to add them: everything is on the Chiba page.
For every other store, Tokyo included, open the full list of Pokémon Centers.