In 2010, Kenji Yamazaki made his debut as an actor by starring in the TV drama "The Inspector of Atami".

In 2011, Kento Yamazaki starred in the movie "Control Tower" and began to receive attention.

On July 5, 2015, the manga adaptation drama "Death Note" starring Kento Yamazaki and Masataka Wada was aired.

In 2016, Kento Yamazaki won the Best Newcomer award at the 39th Japan Academy Film Awards for her roles in the films "The Untamed Actress" and "Orange".

Between 2016 and 2017, Kenji Yamazaki starred in the anime adaptation films "Wolf Girl and Black Prince", "April is Your Lie", "JOJO's Bizarre Adventure: The Unbreakable Diamond Chapter One", and "Nanxiong Saiki's Disaster". With this series of anime adaptation works, he was known as the "Little Prince of Manga" by the audience. Afterwards, Kenji Yamazaki underwent a series of transformations in order to break free from the traditional image of being a "high school student" in the manga adaptation. In the inspirational business drama "Riko" aired in October 2017, he portrayed the ambitious young character of Daichi Miyazawa.

In 2018, Kenji Yamazaki played the role of Shindo, a young doctor with autism and communication difficulties, in the medical drama "Good Doctor". He also won the Best Actor award at the 98th Japan Drama Academy Awards for this role; In the same year, Keno Yamazaki won the Asian Emerging Artist Award at the iQiyi Scream Night Awards ceremony.

In April 2019, the movie "King of the World" starring was released; On August 23rd, Kenji Yamazaki's first voice acting work "Ninomiya" was released.

On December 10, 2020, the anime adaptation series "Alice in the Land of Dying" starring Kento Yamazaki was aired, in which he played the role of Ryohei Arizumi. As of December 26 of the same year, the series not only achieved the highest viewership in Japan, but also became the most watched live action Japanese drama in the world.

In 2024, the movie "Onmyoji 0" starring will be released.