What is the first name of the person who joined Ondekoza when he was 19?  Answer the above question based on the context below:  A number of performers and groups, including several early leaders, have been recognized for their contributions to taiko performance. Daihachi Oguchi was best known for developing kumi-daiko performance. Oguchi founded the first kumi-daiko group called Osuwa Daiko in 1951, and facilitated the popularization of taiko performance groups in Japan.Seidō Kobayashi is the leader of the Tokyo-based taiko group Oedo Sukeroku Taiko as of December 2014. Kobayashi founded the group in 1959 and was the first group to tour professionally. Kobayashi is considered a master performer of taiko. He is also known for asserting intellectual control of the group's performance style, which has influenced performance for many groups, particularly in North America.In 1968, Seiichi Tanaka founded the San Francisco Taiko Dojo and is regarded as the Grandfather of Taiko and primary developer of taiko performance in the United States. He was a recipient of a 2001 National Heritage Fellowship awarded by the National Endowment for the Arts  and since 2013 is the only taiko professional presented with the Order of the Rising Sun 5th Order: Gold and Silver Rays by Emperor Akihito of Japan, in recognition of Grandmaster Seiichi Tanaka's contributions to the fostering of US-Japan relations as well as the promotion of Japanese cultural understanding in the United States.In 1969, Den Tagayasu (田耕, Den Tagayasu) founded Ondekoza, a group well known for making taiko performance internationally visible and for its artistic contributions to the tradition. Den was also known for developing a communal living and training facility for Ondekoza on Sado Island in Japan, which had a reputation for its intensity and broad education programs in folklore and music.Performers and groups beyond the early practitioners have also been noted. Eitetsu Hayashi is best known for his solo performance work. Hayashi joined Ondekoza when he was 19, and after parting from the group helped found Kodo, one of the best known and most influential taiko performance groups...
Eitetsu