Atsushi Iyono, Saya Yamamoto, Takashi Shimizu (Okayama Univ. of Science), Shigeki Aoki (Kobe Univ.), Hiroki Rokujo, Toshiyuki Nakako, Kunihiro Morishima, Mitsuhiro Nakamura (Nagoya Univ.) and Koichi Kodama (Aichi Univ. of Education) for the GRAINE experim