JR West offers a number of rail passes for a variety of travel itineraries. Since I'm focusing on travelling from Hiroshima to Osaka (or Kyoto), there are two specific rail passes that cover that route: the Kansai-Hiroshima Area Pass, and the Sanyo-San'in Area Pass.
Cost & Coverage
The Kansai-Hiroshima Area pass is cheaper, at 13,500 yen (if purchased from outside Japan) for 5 consecutive days, and covers a good amount of track: from Hiroshima, you can go a bit west up until Iwakuni, and then eastbound to Kyoto and a little bit further. However, it does NOT allow for reserved seats on the shinkansen (bullet train): you can only buy non-reserved tickets. You can still take any bullet train (as long as it has unreserved seats) and it also covers all other limited express/rapid/local trains.
Sanyo-San'in Area Pass
The Sanyo-San'in Area Pass is more expensive, at 19,000 yen (if purchased outside Japan), but is usable for 7 consecutive days and covers a slightly wider area, especially westward: you can go as far as Fukuoka on this pass. On the east side, it's about the same. Another perk of this pass is that you can reserve seats on the shinkansen (including the fastest trains, like the NOZOMI), and while also covering all limited express/rapid/local trains.
Note that both passes only allow use of the bullet train up until Osaka (via Shin-Osaka Station), because the shinkansen from Shin-Osaka eastbound (to Tokyo, via Kyoto) is not managed by JR West, but JR Central. You can still use this pass to travel from Osaka to Kyoto, but only via express/local lines. The rapid line takes about half an hour.
Incidentally, both passes also include use of the JR West ferry from Hiroshima to Miyajima. But if you're in Hiroshima for at least three days, I would recommend just using the Visit Hiroshima Tourist Pass, which for 1000 yen covers 3 consecutive days of travel within Hiroshima and the ferry to Miyajima. These passes are expensive, so they're better off being used for long-distance trips.
Which is better? When I travelled, I got the Sanyo-San'in Area Pass because I was with my parents, and we wanted to make sure we could reserve seats and sit together. If you're travelling alone and aren't too worried about the possibility of having to stand on the shinkansen (generally unlikely, unless you're going during an extremely busy travelling season), the Kansai-Hiroshima Area pass should do just fine. If you'd rather just be able to reserve seats, or you want to travel outside of the area covered by the Kansai-Hiroshima Area pass, then the Sanyo-San'in Area pass is probably your best bet.
Why Use a Rail Pass?
Consider this, too: from Hiroshima to Shin-Osaka on the shinkansen, an unreserved seat is already 9,710 yen (for a reserved seat it's 10,440 yen during low season). That's already about half of a rail pass, used in just one day! And you have 4 or 6 more days to use the pass to travel around to smaller cities that you may not necessarily want to stay overnight in, but still want to check out. Day trips are my favorite way of going around, since that minimizes the number of days I spend lugging my bags on trains: I can just grab my day bag and pass and go!
Alright, so where might you go on one of these passes? Here are some of my suggestions! (Note: all reserved ticket costs listed are for low season; high season is a little bit more.)
From Hiroshima (Sanyo-San'in Area Pass only)
- Fukuoka (via Hakata Station): Just an hour away by a direct shinkansen, you can check out Hakata if you're using the Sanyo-San'in Area pass. Fukuoka is a big city that I think is worth staying at least a few nights in, but if you're tight on time and you want to check it out for a day, you definitely can with this pass. Cost for one-way (reserved): 9,150 yen.
- Yamaguchi (via Shin-Yamaguchi, followed by a local train to Yamaguchi Station): about an 70-100 minutes depending on layover time and which shinkansen you take, Yamaguchi is a small city/large town that's a nice break from the big city bustle. They have shrines everywhere, and their tourism site features a recommended walking course around the city. Cost for one-way (reserved): 5,590 yen.
Okayama/Kurashiki: I'm pairing these two together because I think you could feasibly do both in a day, and to access Kurashiki you need to go through Okayama Station anyway. Okayama is most famous for its castle (aptly named Okayama Castle) which is also right next to Korakuen Garden, which is considered one of Japan's three best landscape gardens. The castle is a reconstruction, but if you like castles, it's worth checking out: there's also a combination ticket that allows for entrance to both the garden and the castle. I would recommend the garden, which is probably one of the largest gardens I've ever seen in Japan, and well worth visiting if you like gardens. The city also has a shopping street, but not too much else in terms of tourist attractions, so if you're done with the castle and/or garden early enough, you can head to Kurashiki for the afternoon, just 17 minutes away. Kurashiki (which I wrote a longer article on before, if you're interested) is a quiet town known best for its historical area, which has tree-lined canals and streets lined with historical buildings that now house various shops and restaurants. It's a beautiful place and I would highly recommend going to visit for a quiet day away from the city. To Okayama, a one-way ticket (unreserved/reserved) comes to 5,500/6,230 yen. The ticket from Okayama to Kurashiki (local line) is just 320 yen, but still covered by the pass.
- Another small town connected through Okayama is Onomichi, which is a port town. I didn't get the chance to visit because of time constraints, but Onomichi has many temples and a picturesque port. There are a few ways of getting to Onomichi, with the fastest being about 45 minutes via a shinkansen and then a local train, costing about 3,050/3,780 yen.
- Himeji: another spot we weren't able to visit due to time constraints, Himeji is a popular tourist spot primarily for its castle. It's also just half an hour away by shinkansen from Shin-Osaka, and would normally cost 3,220/3,950 yen for a one-way trip.
- Kobe (via Sannomiya Station): close enough that it's accessible via local train in just half an hour, Kobe has a pretty large shopping street, a large landscape garden, a mountain offering panoramic views, and - of course - Kobe beef, at the source. Since it's local, it's just 550 yen to get to Sannomiya Station from Shin-Osaka.
- Nara: roughly an hour from Osaka, it's worth noting that the rapid service and limited express services take about the same amount of time, despite the limited express costing twice as much: but if you're using a pass, you can use either anyway. Nara, of course, has plenty to see: the Giant Buddha, temple, and deer, to name the most famous. Local trains cost about 920 yen.
- Kyoto: I already wrote about it above, but the trip from Shin-Osaka to Kyoto (by limited express/rapid/local trains) is covered by this pass: both take the same amount of time, but the limited express costs a fair bit more. The rapid service is just 560 yen.
Sample Itinerary for the Sanyo-San'in Area Pass (reserved ticket prices):
- Hiroshima, day trip to Yamaguchi: 5590 x 2 = 11,180 yen
- Hiroshima, day trip to Okayama + Kurashiki: (6,230 + 320) x 2 = 13,100 yen
- Hiroshima, travel to Shin-Osaka: 10,440 yen
- Travel around Osaka: any JR trains are free!
- Osaka, day trip to Himeji: 3950 x 2 = 7,900 yen
- Osaka, day trip to Nara: 920 x 2 = 1,840 yen
- Osaka, day trip to Kobe: 550 x 2 = 1,100 yen
With the Hiroshima-Kansai Area Pass, a sample itinerary might be days 2-6 from the above itinerary: those five days also would add up to well over the pass' cost of 13,500 yen, even at the lower unreserved ticket prices.
Whew! That's all from me, thanks for reading all the way through. I hope this provides some help or inspiration to anyone planning a trip to this area!