It's true tho that Japanese universities have a problem with labs communication. In the former university I was a MEXT student in, there was at least three labs that could have collaborated on topics that my lab was focused one. Granted, one professor welcomed me in his lab to do some stuffs with his students. But otherwise it was like little fiefdoms taking pride in doing things alone. This is contrasting with what's going on (at least in intention) in French research.