If you intend to visit Osaka, I would recommend going to the district of Shin Umeda City. There is one particular point of interest: Umeda Sky Building, built in 1993 by Hiroshi Hara. This huge building has a very special architecture, as it consists of two 40-story towers connected by a circular observatory.
First, have a break in the Floating Garden Observatory from where you can admire the city behind huge windows. Going up some stairs, you find yourself out on the stunning Lumi Sky Walk which describes a phosphorescent milky way to the ground. The 360-degree aerial views of Osaka are absolutely stunning, especially at dusk and at night.
Umeda Sky Building: from 10am to 10:30pm, ¥700 entry fee for adults.
How to get to Umeda Sky Building
15 minute walk from Osaka-Umeda station
Location reachable with the JRP : order your Japan Rail Pass (from ~US$ 265)
¥700 (~US$ 6.30)
Get your Japanese Yens free of charge
Open daily from 10am to 10:30pm (last entry at 10pm)
How long / when to visit
Approximate tour time: between half an hour and an hour
Recommended period: clear weather and mild temperature / day, dusk or night at the preference of oneself
梅田スカイビル (Umeda Sky Biru)
空中庭園 (Kuchu teien : the floating garden)