best way to use JR Pass

I plan to visit tokyo, hiroshima, kobe, osaka, and niigata using the 7-day JRPass. Please advise how best to go about the trip. I want to start from tokyo and return to tokyo every day during this trip as i will be staying with a relative there.

The rail pass is extremely good value especially if you travel around, but im not sure if you realise how far between tokyo and hiroshima! it will take you about 6 hours on the train! i think it is impossible to do this in a day trip. But i definately recommend Hiroshima, it is an amazing city. you should consider staying somewhere in the middle at least for one night! i did a day trip to Hiroshima from Osaka, so maybe you can stay one or two nights in Osaka and see that area then. hope this helps.

You will be spending 4-6 hours, at least, travelling time everyday if you are to station at Tokyo. Since you have a JR Pass, spend a couple nights on the free night trains for the experiences and time saving purposes.

Day trips from Tokyo by JR Rail Pass:
Hiroshima: first hikari leave Tokyo 06.36 h one transfer arrive Hiroshima 11.33 h,
last return lv Hiroshima 18.09 h one transfer arrive Tokyo 23.19 h
Osaka: first hikari leave Tokyo 06.36 h arrive ShinOsaka station 09.36 h , last return lv 20.23 h arrive Tokyo 23.19 h .
Kobe: the JR station Sannomiya for Kobe inner city is about 20 min train ride from ShinOsaka
Niigata: first leave 06.08 arrive 08.16 h, last return 21.29 h arrive Tokyo 23.40 h.

1. Tokyo to Osaka: JR overnight buses are valid on a JR pass, so you could leave Tokyo around 10 to 11 pm and arrive in Osaka around 6 to 7am next morning. Thus you could optimize your stay in Osaka and Kobe until the last Shinkansen Hikari leaves Shin-Osaka for Tokyo at 20:23.

2. To get to Hiroshima from Tokyo overnight, you could catch the Sunrise Izumo-Seto from Tokyo (22:00), which arrives at Okayama at 6:27am next morning and change to theHikari train which leaves Okayama at 6:48am and arrives at Hiroshima at 7:29am. Thus you could stay in Hiroshima until 18:09. The Sunrise train has "Nobinobi seat" carriages, a carpeted semi private compartment with a blanket, and shower booths (310yen).

Having said that, I would recommend you to stay overnight somewhere other than Tokyo e.g Osaka, at least a couple of nights for your comfort. Always having to concered about next train departure can be very stressful.