Earlier quoted context omitted.
>Store the name in two fields, have the users bend over our western form standards but be able to search and sort easily. You can't search and sort easily if the names are stored in Japanese. You need 4 fields for that. Edit: now that I think about it I could think of a disgustingly hacky way to squash them into 2 fields and retain those properties, and by extension into a single field and retain those properties.
Why would you need 4 fields?
Even then, there are two accepted standards for sorting kana. Japanese is full of these kinds of fun exercises in writing system complexity.