Japanese groups play an active role in the CALICE collaboration, which is developing the calorimeter technologies which we plan to use for the ILC detectors. The main novel aspect of the devices being developed by CALICE is the fine readout granularity, of typically around a cubic centimetre. This allows particle showers, especially those within hadronic jets, to be individually identified and measured, enabling the optimal use of so-called particle flow reconstruction to measure jet energies with unprecedented precision.