Japan-Rail.net

A fine place to watch local trains (on the Kure Line, Geibi Line, and San’yo Line) approaching Hiroshima Station is Atago Level Crossing. This level crossing is at the east end of Hiroshima Station, not more than a few tens of metres from the platforms.
It is about a five-minute walk from Hiroshima Station to Atago [...]

The 0-series Shinkansen are relatively easy to photograph, since they operate all-stations-stopping ‘Kodama’ services: the slowest services on the San’yo Shinkansen. Because of the frequency of ‘Nozomi’ (and ‘Hikari’) services, which do not stop at every station, ‘Kodama’ services have frequent station stops of several minutes, waiting for faster services to overtake. These longer station [...]

In general, there are no problems with taking photographs of trains and railways in Japan. It is important, however, to pay attention to the following points:

Do not trespass. If at a station, for example, stay on the platform and do not go past ‘No Entry’-type barriers or signs.
Ensure that you do not interfere with the [...]