JSPS has published an interview article entitled “Career Advancement through Multiple JSPS Fellowships” with postdoctoral researchers who have been accepted into multiple programs.

The article includes interviews with senior fellows who were accepted into the three programs※, how they were accepted, research life in Japan, advice for junior fellows, and more.
※Postdoctoral Fellowships for Research in Japan(Summer Program, Short-term, Standard)

The articles are available on the JSPS website at the following URL, so please take a look.
https://www.jsps.go.jp/file/storage/j-publications/data/Career%20Advancement%20through%20Multiple%20JSPS%20Fellowships.pdf