is a Japanese singer, actor and haiku poet who is a member of boy band Kis-My-Ft2 and its derivative group Busaiku() under Starto Entertainment. His nickname is Watter and Shi-sho (master in Japanese).
He joined Johnny & Associates on February 4, 2001. He was taken to the audition site by his brother who told him to go to futsal. At the same audition, Toshiya Miyata and Takashi Nikaido, who later became members of Kis-My-Ft2 also participated.
As a trainee (Johnny's Jr.), he was a member of J-support (later renamed K.K.Kity) until 2003, in April 2004 he was selected as a member of Kis-My-Ft. and started working with Hiromitsu Kitayama and Taisuke Fujigaya, and in July 2005, Yuta Tamamori, Toshiya Miyata, Kento Senga, and Takashi Nikaido joined to form Kis-My-Ft2 and became its members.
In October 2010, he made his first drama appearance in Fuji TV's "Freelancer Buys a House".
Kis-My-Ft2 made their CD debut with "Everybody Go" on August 10, 2011, seven years after their formation.
On December 13, 2013, Busaiku was formed from Kis-My-Ft2 with Kento Senga, Toshiya Miyata and Takashi Nikaido produced by Masahiro Nakai who was a member of SMAP.
He is also known for his talent in composing haiku. He has twice won the in-program Haiku Meijin Tournament on Mainichi Broadcasting System variety show "Prevato," which he has appeared on irregularly since 2015.
On January 26, 2023, he announced on the official website of Johnny & Associates that he married a civilian woman, becoming the first Kis-My-Ft2 member to be married.
Yokoo is known for his culinary skills and even has a regular column in a cooking magazine, but he also has an unusual license. In 2017, Yokoo obtained a first-class license as dismanling for tuna on Kis-My-Ft2's variety show Kis-Mileage, which aired on TV Asahi. A first-class license as dismanling for tuna is a difficult license to dismantle large tuna to make sushi and sashimi using a long, dangerous knife at shows and other events while enlivening the occasion with conversation. At the time, there were only seven people in Japan who held a first-class license, and none of the celebrities had obtained it. Yokoo failed the test once when he took it in March, but he repeatedly trained on his own between jobs and took the final test at the Tsukiji fish market in Tokyo. He then passed, albeit with a condition ("Although his skills was passable, he has no experience performing shows alone, so he must perform shows with another first-class dismantler for a while").
For activities as a member of Kis-My-Ft2, see Kis-My-Ft2#Group activities.