When I was a child (living in an Asia), we had a separate toilet and a bidet (side by side). The awkward part was moving between the two. Even with that separation, accidents can happen (i.e. feces in the bidet). I wonder if the single Japanese toilet is superior to two separate seats (toilet + bidet) in regards to hygiene.
Oh man I feel your pain. My family had one of those here in Brazil and I hated when this happened. Anyway I do not live in the house I was raised anymore and now every modern apartment in Brazil only have a toilet, this is sad for me.