Nice find. It says that 白山俊太郎 (Shuntaro Shirayama) was in charge of the music/sfx. This article says he joined in April 2016:
http://www.itmedia.co.jp/lifestyle/a...3/news024.html
The other member 西村和真 (Kazuma Nishimura) was in charge of sound implementation (programming the music/sfx into the game).