If you are on a bus, you can collect pokemons or items easier and faster.
Free Wi-Fi is available on Toei buses operating in the capital. For more details, please see the following link.
Once you connect to the freeWi-FI, you can play POKEMON GO without worrying about packet communication charges. Besides, you can come across wild pokemon just by sitting there as well as you are on a train or in a taxi. You can also hatch the eggs.
Moreover, there are many bus stops in Tokyo and buses often stop, so you can easily find Poke Stops nearby. By taking a bus, you can play POKEMON GO easily and quickly without walking in a hot and humid weather. Give it a try!