Kenji Matsui: Suspensions (オール吊りの本, Oro tsuri no hon)
According to SMpedia, Kenji Matsui (1940–2013) was an ”amateur” nawashi, who’s work was sometimes published anonymously. He had some relations with, among others, Akechi Denki. Kenji in turn was an important influence for Kamui Jubei and the ”Mumonbaku”-style.
Kenji Matsui: http://smpedia.com/index.php?title=松井健二
Jubei Kamui: http://smpedia.com/index.php?title=神威十兵衛
Mumonbaku-videos on TouTube: http://www.youtube.com/user/mumonbaku
Editor: Tetsuro Nakajima
Publisher: Sanwa, 1999
ISBN: 4-88356-710-9
PS Sin recently published an interview with Jubei Kamui, also addressing the ”mystery” of Kenji Matsuji”. It can be read here: http://www.kinbakutoday.com/kamui-jyubei-san-mystery-matsui-kenji/