He left Johnny & Associates on 9 September 2017,[4] together with two other SMAP members, Goro Inagaki and Tsuyoshi Kusanagi and entered CULEN, a Japanese talent agency.

[5] On 22 September 2017, they launched a new project, "atarashiichizu" ("新しい地図", meaning "New Map") as their common fan site, supported by various Japanese leading creators.

The album features songs written by Katori, as well as collaborations with artists such as TeddyLoid, BiSH, Kreva, Kishidan, and Scha Dara Parr, and more.

[10] He also contributed to writing some of the songs on the album, such as the titular "Tokyo SNG", "Kongaragatte", "Shingopation", and "Catharsis", to name a few.

[citation needed] Katori serves as the main vocal on the track, performing alongside SEVENTEEN's Mingyu, Jeonghan, and Seungkwan.

He has also starred in many high-rated television series, such as Hito ni Yasashiku (2002), Saiyuki (2006), and Bara no nai Hanaya (2008).

[15] From October 1998, Nakai and Katori launched their own variety program, SataSma, which was created and aimed towards younger viewers and families.

In December 2000, the trademark phrase "Ohha", used by Katori, won the Ryukougo Taisho, an annual traditional event of announcing words that describes that year.

From 2000 to 2001, Shingo Mama promoted the use of Ohha as part of a Ministry of Education campaign to encourage family communication.