In the entire world, Keiyu (Keiyu 
) is quite a rare masculine forename. The given name Keiyu is habitual in Eastern Asia, particularly Japan, where it is quite a rare boy's name. Much less frequently, Keiyu is the last name as well as the forename.
Lam, Tanaka, Tomita, Hamada, Hirata, Fujita, Oshima, Ohshida, Sakurai, Kojima, Shimizu, Akiyama, Matsumae, Takenaka, Nakamura, Nakagawa, Nakajima, Yamauchi, Matsumoto, Shibata, Komori, Kawara, Kawano, Ito, Ota, Mori, Chan, Kato, Hase, Fujii, Inoue, Ishii, Ikeda, Onuki, Okada, Ogura, Ohara, Morita, Miyagi, Sakata, Suzuki, Kaneko, Kobayashi, and Nishimura