He and his partner, Ryo Tamura (田村亮?), form the Japanese comedic duo (お笑いコンビ owarai kombi?) known as "London Boots, Mark1 Mark2" (ロンドンブーツ1号2号?). Though the two share the same surname, there is no family relation. The pair started their career by performing comedy on the streets of Tokyo.
Before he was famous, Atsushi attended an Industrial high school in his hometown of Shimonoseki. He was suspended twice during that time, once for smoking and once for cheating on a test. Atushi was also a member of a band before becoming interested in comedy. For his first comic act, Atsushi teamed up with a classmate from school. They called themselves Umaseki Fugutarō and Fugunosuke, a name they derived from Shimonoseki, and fugu or pufferfish, a dish famous in the region. Atsushi eventually teamed up with Ryo Tamura after relocating to Tokyo. They chose to go by the name of “London Boots” initially because it was the name of a fictional comedy team. While “London Boots” does not have any particular meaning in English, in Japanese it refers to the knee length platform shoes worn by some Japanese girls.
The London Boots (ロンドンブーツ London Boots Ichi-go Ni-go?) act is typical of Japanese comedy duos in the sense that one person in the duo criticizes and abuses his partner who in turn plays the part of a stooge. While Atsushi was once on the receiving end of the duo's jokes, he has since taken the dominant role and does not hesitate to subject Ryo to severe acts of embarrassment.
As London Boots, Atsushi and Ryo also serve as the hosts of many shows and special programs on Japanese television. These programs often derive humor from tricking and humilliating other people, often in very cruel and calculated ways. An example of this could be seen on a former segment known as "Stinger". This segment begins with a man who comes forth with doubts over his girlfriend's faithfullness. In an attempt to settle these doubts, a hired actor known as the stinger is brought to the program. The stinger's objective was always the same. He must introduce himself to the unsuspecting girlfriend in public and quickly try to seduce her in to accompanying him to "his home". Secret cameras and microphones follow the progress of the stinger to see if he is successful. If this is the case, the woman will step in to a room and unexpectedly find herself standing in front of her boyfriend, London Boots and a camera crew. Atsushi will use this and other similar opportunities to instigate shame and callously assign blame. Not even Japanese television personalities and other celebrities are exempt from Atsushi's trickery. Another example of Atsushi's style of humor is when he filmed and exposed his partner Ryo going to a Japanese style brothel.
Recently, Atsushi has gained a role as an actor in a large NHK historical drama. Atsushi, who loves Japanese castles and the Japanese Middle Ages (characterized by civil wars), also collects Japanese swords. He once wanted to become a voice actor, but audition judges often pointed out that he has a hard time changing his voice. However, he finally landed a major role as voice actor (seiyuu) for Yoichi Hiruma (Eyeshield 21), who, like Atsushi, often tricks people, and has as a "servant" like Ryo. He is currently the host of his own show "London Hearts", along with his partner Ryo. He is also the Japanese voice of Butthead from Beavis and Butthead and the voice of Bart Simpson in The Simpsons Movie only, Junko Hori being the regular Japanese voice of Bart. He also provides the voice of Paradox in Yu-Gi-Oh! 3D: Bonds Beyond Time.
On May 31, 2006, Atsushi privately became the vocalist of Jealkb, making his indie debut with the song "metronone", which made it to the top of the indie charts. He performed live with his band on April 2007 and made their major debut with the song Chikai, released on October 31, 2007. He is the leader and singer of the band and the band as so far released 9 singles and 2 albums.