Brainstorming

I had the idea for a Kingdom Heartss 358/2 Days futanari story between Roxas and Xion. Much like my Naruto story it will also be romantic. For a story like this, however, I feel it might need to have a bit more chapters to it in order for it to be effective.

So far my ideas are:

1. Roxas walking in on Xion fucking a Dancer nobody at TWTNW (it looks female...). (How he finds out about her).

2. Roxas and Xion in The Cave of Wonders; Roxas tops.

3. Them in Neverland, floating in the air while having sex. (Not sure who should top here)

4. Them at the Twilight Town clock tower, eating ice cream. Xion gets excited about the way Roxas is eating his popscicle and pounces on him; Xion tops.

Looking for suggestions on which other worlds I should use and what should happen in them. I'd particularly like an idea involving Wonderland.