You could head out to Kobe aswell if you're going to Osaka, Rokko Mountain and the Farm up there is really nice not to mention the spectacular view, theres 'Herb Park' on the mountainside just north of Kobe city in Shin Kobe (walking distance) if she like flowers and perfumes/herbal stuff, and Harbourlannd has good mix of interesting shops and restaurants, theres also a romantic ferris wheel there right on the harbour if you want to propose for the 3rd time if she says no at Osaka castle and at Kabukicho love hotel...