Actually, Taipei and Kaoshiung looks alot like smaller and medium sized Chinese cities, metropolis like Tokyo, Shanghai, Beijing, Guangchow looks alot more modern, the smaller and curved streets look much alike other chinese cities before modern city planning occured in china, been to japan a couple times too, the only thing that makes those 2 alike are the mountainous terrain.
From the buildings it looks like te best time of Taiwanese economy at least construction wise is during 1980-1990 during JiangJinkuo's ruling time(after 1995 most of the planned buildings during 80s have been finished and the building boom stopped), which is also about the peak time of Japanese economic development, so many buildings might look similer IDD since they are from the same period.