1. NAIST, Japan
2. RIKEN, Japan. hiroki.ouchi@is.naist.jp
3. Tohoku University, Japan
4. RIKEN, Japan. sosk@preferred.jp
5. Preferred Networks, Inc., Japan. jun.suzuki@tohoku.ac.jp
6. RIKEN, Japan. yokoi@tohoku.ac.jp
7. Langsmith, Inc., Japan. kuribayashi@tohoku.ac.jp
8. RIKEN, Japan. yoshikawa@tohoku.ac.jp
9. RIKEN, Japan. inui@tohoku.ac.jp