Osaka B-grade sightseeing
Tsutenkaku通天閣 in Osaka near the zoo is great for a taste of retro Osaka, if that’s of interest. Very lively area but also very…dated. People who like their sight-seeing squeaky clean and brand-spanking new will get a shock.
If okonomiyaki お好み焼き is your thing, Osaka also has negi ネギ焼き which is similar but made with spring onions instead of cabbage. The best place is Yamamoto Negiyaki (http://www.negiyaki-yamamoto.com) and the main branch is at Juso十三 one stop from Umeda/Osaka梅田・大阪. This is often a queue, and they don’t allow photos in the restaurant, but it’s hardcore—deep Osaka
You can travel from central Osaka to central Kobe in roughly 20 minutes on either JR, Hankyu 阪急 or Hanshin阪神 to Sannomiya (written 三宮 or 三ノ宮for JR). They arrive at the same point, take roughly same time and the fares are similar.
In terms of sight-seeing, I hesitate to suggest. Kobe for me is a “lifestyle city”—great to live here, but not sure where to take people who visit. It’s a bit like Yokohama 横浜 in many ways–there’s Chinatown (Nanking-machi 南京町) near Motomachi 元町 and there’s some old Western-style houses 異人館 up the hill from Sannomiya 三宮 at Kitano北野.
Sannomiya 三宮 is the heart of Kobe. Kobe Station (JR) 神戸駅 is not the centre (it’s the pre-WWII centre) but it IS close to the Harborland development, a more modern shopping mall, by the harbour.
Arima Onsen 有馬温泉hot springs is only 30 minutes from Sannomiya, I cannot tell you anything about Arima. Must be nice – up in the hills, which are alive with the sound of onsen
My personal interest in Kobe (as with many cities) is the grungy/retro side. The city is dying back (as is much of Japan) and the decay just outside the city centre has a quaint Showa-era feel, with funky shops and eateries. The low-life highlights for me include the shopping arcade below the JR train tracks between Sannomiya, Motomachi and Kobe stations 高架下 (locals call this series of 7 arcades Motokohモトコー), and Shinkaichi 新開地.
For hot springs, I can recommend Tarumi Taihei-no-yu垂水温泉太平のゆ in Tarumi垂水 which is adjacent to the Outlet Park (identical to every other outlet park in Japan) Views from here over Awaji Straits淡路海峡 and of the bridge to Awaji Island淡路島
The nearby Suma 須磨 beach area is also cool and groovy. For something completely different, the port town and seafood markets of Akashi 明石 are also not far from Kobe and the tamago-yaki 玉子焼き which is the takoyaki たこ焼き (octopus balls) of Akashi is extraordinary there. It is served with a dipping broth, and is known as “Akashi-yaki” everywhere except in Akashi.