Please be aware that Tokyo and Taipei has multiple airports and that these results are for all airports serving the city.
The best month to fly between Tokyo and Taipei is September and the most expensive month to fly is March. (Average prices, based on 567 datapoints.)
The cheapest airline flying from Tokyo to Taipei is Peach Aviation. They are 70% cheaper than Cathay Pacific. (Average prices, based on 579 datapoints.)
The best time to fly is at around 22. (Average prices, based on 651 datapoints.)