Gorō Yamaguchi (山口 五郎,February 26, 1933 – January 3, 1999) a Japanese shakuhachi (vertical bamboo flute) player, was known for his musicality, phrasing, impeccable technique (and modesty) in solo and ensemble performances. He headed the Chikumeisha shakuhachi guild and became a world-famous Japanese performer and teacher. In 1967-68 he was appointed Artist in Residence at Wesleyan University in Middletown, Connecticut (USA).
This piece is one of the three oldest and most important of the Kinko Ryu Honkyoku along with “Shin No Kyorei” and “Koku Reibo”. These three pieces are also referred to as the three pieces of Bekkaku (special rank, i.e.., The Traditional Three).
According to the “Kyotaku Denki” diary, this is a piece which the monk Kyochiku Zenshi (also known by the name of “Kichiku” who was a student of Hotokokushi Kakushin – founder of the Fuke Shu) received in a dream while asleep in Koku Zodo Temple located at the foot of Kishu Asakuma Mountain during his travels as a Komuso. In his dream, while gazing upon the moon from a boat, he heard two different strange flute melodies. As soon as he awoke, he tried to play this strange music with his Shakuhachi and later returned to his teacher Kakushin to report on what had happened and what he had done. The master Kakushin named the first melody “Mukaiji” and the later “Kokuji”. The term “Reibo” is just a suffix later added on by Kinko Kurosawa which has no special meaning.
Mukaiji was transmitted to Kinko by Ikkei at Kishu Asakuma Yama Koku Dozo in the year Kyoho 13.