As far as I'm concerned, it's a guy's.
Cause i know a guy who has that name.
Nakamaru Yuichi from KAT-TUN.
Yuichi Hibi was born in 1964.
Yuichi Onda was born in 1980.
Yuichi Kodama was born in 1975.
Yuichi Akasaka was born in 1967.
Yuichi Ogawa was born in 1946.
Takahashi Yuichi was born in 1828.
Yuichi Nakagaichi was born in 1967.
Yuichi Nakamaru is 178 cm.
Yuichi Nakamaru was born on September 4, 1983.
Yuichi Nakamaru was born on September 4, 1983.
Yuichi Nishimura was born on April 17, 1972.
Yuichi Nishimura was born on April 17, 1972.