Over the next couple of months, I will be applying to about 30 jobs. Two-thirds of the jobs have applications in English. The downside for that is that this means most of them are just for teaching English. The big upside is that I can write and edit all of the documents by myself. For the applications in Japanese, the following type of document request is pretty typical:
(4)採用後の研究計画（それぞれA4版1枚程度）
(4) これまでの教育・研究及び社会貢献の概要をふまえて、今後の教育・研究及び社会貢献への抱負を述べた文書（任意の様式で3000字程度）
(3)担当可能科目及び現在の研究テーマ（指定の用紙に記入）
(7) 研究の抱負（1,500字以内、A4判縦）
4）研究概要と研究計画書（本学所定の様式）
４．これまでの研究・教育の概要（２，０００字程度、様式随意）１部
[The numbering is as they are enumerated in the requirements on JREC].
The great part is that this feature is not that different from an application in America. One minor difference is that they seem to emphasize the research you have already done more in some of the possibilities. Also, some of them seem to want you to mix the research and teaching statements together (???). The frustrating part as a non-native Japanese speaker is that it's quite difficult to edit all of this together. Note that one says A4-length, another says within 3000 characters in their form for both teaching and research. Another says 1500 / A4. Another says to use the provided form. Still another is 2000 characters.
I am approaching this in the same way that I would a Western university when applying for positions that closely fit my abilities. I made documents outlining my teaching philosophy and my research program last year as part of the pre-application phase for jobs over the summer. But this time it helps that I've spent several months actually working on these projects -- in two cases successfully (1 for 4 in Western journals / 1 for 1 in Japanese conferences) and in one case very unsuccessfully (I have restarted that project after doing significantly more reading -- including trying to do some of it in Japanese).
For jobs outside of my field, I am modifying what I write somewhat. Instead of "哲学者として", I write "思想学者として." And I emphasize my flexibility for 教養科目(general requirement courses). I am not sure what voice this should be written in, but I have been writing my materials in である instead of です体 and received assistance from a tutor at my school until the semester wound down at the beginning of August.
As a consequence, I have a basic version of the research statement. In it, I outline (a) what I have already written [primarily in terms of the dissertation] and (b) what I am looking to write as two new projects. I will probably have another Japanese friend or friend look it over and see what they think.
A slightly less common feature in Western applications that is pretty common here is to ask what contributions you've made to society. I've seen that as a section on the school-provided 履歴書(CV) documents and as a separate required document. For one university, their English application asks you what your "Social Contract" with the neighborhood would be.
