This blog offers research information on Japanese archaeobotany as well as my interests.
I found an interesting website (just only in Japanese).
It is produced for science education of primary and junior high school students, but its content includes STARCH GRAIN. Please click "DENPUNRYU (in Japanese, starch grain)".
Denshi-Kenbikyo De Miru Micro No Sekai (in Japanese, Micro World by Scanning Electron Microscopy)