Family name Ken-Ichi (健一 
, Ken-Ichi 
) , around the world, is a rare cognomen. The last name Ken-Ichi is habitual in China, where it is a very rare surname, and the United States, where it is an extremely rare surname. More frequently, Ken-Ichi is the forename as well as the last name. Parts of the name also exists independently as a first name Ken, and a first name Ichi.
Abe, Kimura, Tanaka, Toyama, Nigita, Nonaka, Nomura, Hanada, Hirano, Furuno, Futami, Fujita, Ichino, Okochi, Ochiai, Matsuda, Kumagai, Sakakibara, Shinotani, Sugimoto, Kawamura, Nakamura, Kubota, Kogure, Suzuki, Shinjo, Ito, Mori, Sato, Ando, Arai, Kato, Hori, Hino, Ueda, Maeda, Takahashi, Miura, Fukui, Inoue, Inudo, Ishii, Ihara, Iwaya, Onami, Okaue, Ogawa, Yokoi, Hiasa, and Yamaguchi