, known by the stage name is a Japanese comedian, lyricist, actor, novelist, and film director.
Gekidan is mainly known his improvisational ability and for his style of physical comedy. He is represented with Ohta Production.
Kawashima's parents were employed by Japan Airlines (his father was a pilot; his mother was a flight attendant). Due to the nature of their occupation, Kawashima lived in Anchorage, Alaska, for three years as a child, from second to fifth grade.
In 1992, while in his first year of high school, Kawashima appeared on the variety program Tensai Takeshi no Genki ga Deru Terebi!! and garnered the attention of Ohta Production to sign him as a comedy talent. He began activities in a kombi called "Suplex", but were relatively unsuccessful. Kawashima transferred and dropped out of high schools multiple times before graduating from Chiba Ritsufunabashi High School at the age of 20. He then went on to enroll in Tà Âhà  Gakuen in Tokyo and specialized in broadcasting arts, graduating in 1999.
Kawashima's unit, "Suplex", disbanded in 2000 and Kawashima continued activities as a solo comedian with the name "Gekidan Hitori", which translates to "one-person troupe". After going solo, Gekidan became vastly more popular and successful in the industry, with numerous appearances in various television and variety programs. He continued to flourish in the following years, even becoming active as an actor in TV dramas and movies.
His wife is tarento , the two married in 17 February 2009 . They have three children, their first daughter was born in September 2010 and their first son was born in July 2016. They announced the birth of their third child, a daughter, born March 2019.
When "Suplex" disbanded, Kawashima needed a new name to continue activities as a solo comedian. Initially, he set up an Internet voting poll with the top two names with the votes being and , which translates to "The Shoreline People". Both were rejected by Kawashima's manager, stating that he "sees no future" for these names in the industry to succeed. During a chat with fellow comedian and script writer Kazuhiro Yasuda, when Kawashima asked Yasuda who is his favorite actor, Yasuda responded with Robert De Niro, but with bad pronunciation, which to Kawashima sounded like "Rohata de Nirà Â", which literally translates to "Niro from the Furnace", and sparked him to suggest the use of the name. This was, however, also rejected by his manager. Kawashima chose the name "Gekidan Hitori" in the end.
Gekidan Hitori is commonly referred to as Hitori or Kawashima by most others in the industry. Tamori, on the other hand, calls him Gekidan. His wife Akane Ozawa refers to him as "Shingo-tan".