No. Only JET alumni with former contracting organisations in Eastern Japan (e.g. Hokkaido) can apply in 2018. Please refer to the list of prefectures below to check whether your former host prefecture is in Western or Eastern Japan.
Western Japan (Kansai, Chugoku, Shikoku, Kyushu, Okinawa); eligible in 2017:
Kansai Region: Mie, Shiga, Kyoto, Osaka, Hyogo, Nara, Wakayama
Chugoku Region: Tottori, Shimane, Okayama, Hiroshima, Yamaguchi
Shikoku Region: Tokushima, Kagawa, Ehime, Kochi
Kyushu/Okinawa Region: Fukuoka, Saga, Nagasaki, Kumamoto, Oita, Miyazaki, Kagoshima, Okinawa
Eastern Japan (Hokkaido, Tohoku, Kanto, Chubu); eligible in 2018:
Hokkaido Region： Hokkaido
Tohoku Region： Aomori, Iwate, Miyagi, Akita, Yamagata, Fukushima
Kanto Region：Ibaraki, Tochigi, Gunma, Saitama, Chiba, Tokyo, Kanagawa
Chubu Region： Niigata, Toyama, Ishikawa, Fukui, Yamanashi, Nagano, Gifu, Shizuoka, Aichi
CLAIR is still investigating whether or not to continue the project beyond 2019.