- Sep.1943
- Nikkei Kokoku-sha, the forerunner of Nihon Keizai Advertising Co., Ltd. established in Nagoya
- Mar.1947
- Yoshinobu Niwa established Nihon Keizai Advertising Co., Ltd. with the capital of ¥100,000 (March 18th)
- Jul.1951
- Branch established in Nagoya
- Mar.1954
- Head office moved to 3-4, Kanda Ogawamachi
- Jul.1954
- Radio TV Media Division established
- Sep.1955
- Branch established in Shizuoka
- Mar.1956
- Started to employ new university graduates
- Apr.1958
- Head office moved to 2-2, Kanda Nishikicho
- Mar.1961
- Capital increased to ¥5,000,000
- Nov.1961
- Construction of headquarter building Nikkei Advertising Company Bldg. completed
- Jul.1962
- Plate Making Division established
- Jan.1967
- Branch established in Osaka (Daikei-sha)
- Jul.1967
- Capital increased to ¥10,000,000
- Dec.1968
- Nikkei Annai Advertising Company (now Nikkei Agency, Inc.) established
- Jul.1969
- Capital increased to ¥20,000,000
- Dec.1969
- Sales branch established in Saitama
- Aug.1970
- Extension and improvement of headquarter building completed Sales branch established in Tama
- Jan.1971
- Capital increased to ¥30,000,000
Sales branch established in Chiba
- Apr.1973
- Sales branch established in Hamamatsu
- Aug.1974
- Sales branch established in Kawasaki
- Apr.1976
- Kawasaki branch moved to Yokohama and renamed as Yokohama branch
- Jan.1979
- Nikkei Kokoku Seihan established
- Apr.1979
- Nikkei Sangyo Advertising Agency Co., Ltd. established
- Jul.1979
- Established Nagoya branch of Nikkei Sangyo Advertising Agency Co., Ltd.
- Mar.1981
- Closed down Nagoya branch of Nikkei Sangyo Advertising Agency Co., Ltd.
and established Nagoya branch of Nihon Keizai Advertising Co., Ltd.
- Jan.1982
- Nikkei Creative Center, Inc. established
- Mar.1982
- Construction of Nihon Keizai Advertising Company's Surugadai Bldg. completed
Head office moved to 3-6, Kanda Surugadai Chiyoda-ku
Capital increased to ¥63,776,150
- Apr.1983
- Business Service established
- Jan.1984
- Nikkei Annai Advertising Company renamed as Nikkei Agency, Inc.
- Mar.1986
- Yoshinobu Niwa became the chairperson
Nobukazu Niwa became the president
Capital increased to ¥89,130,300
- Jan.1991
- CI implemented and corporate brand named as ADEX
Branch established in Kyushu
- Sep.1992
- Construction of Nihon Keizai Advertising Company's ADEX Ogawamachi Bldg. completed
- Jun.1993
- Sales branch in Tama reorganized into sales branch in Tokyo and its office moved to ADEX Ogawamachi Bldg.
- Dec.1993
- Sales branches in Tokyo, Chiba and Saitama reorganized into Tokyo sales office
- Jan.1996
- Tokyo sales office renamed as No.13 sales office
- Aug.1996
- Acquired ADEX Ichibancho Bldg
- Jan.1997
- Yokohama branch and No.13 sales office reorganized into No.14 sales office
- Feb.1997
- TAFF Creative Co., Ltd. established
- Jan.1998
- Shizuoka branch and sales office in Hamamatsu reorganized into Tokai branch
- Apr.1998
- Construction of Nihon Keizai Advertising Company's new building completed
Head office moved to 2-10, Kanda-Ogawamachi, Chiyoda-ku
- Dec.2002
- Extension of Nihon Keizai Advertising Company's building completed
- Jan.2005
- VI implemented
- Dec.2005
- Acquired a Privacymark
- Jan.2006
- Osaka branch renamed as Kansai branch
- Mar.2007
- ADEX DESIGN CENTER Co., Ltd. established
(Nikkei Creative Center, Inc. and TAFF Creative Co., Ltd. merged)
- Apr.2007
- IT Communications Inc. established
- Jun.2007
- ZENRYOKU AGENCY CO., LTD established
- Jul.2013
- ADEX HOKKAIDO established
- May.2015
- Sendai office established
- Jun.2019
- Nobukazu Niwa became the chairperson
Nobuhiro Niwa became the president
- Apr.2020
- Nikkei Kokoku Seihan renamed as ADEX MEDIA DATA CENTER
- Jul.2020
- ADEX Digital Co.,Ltd. established
