Japanese grinder is excellent quality. I mentioned your comment about the paper to my wife.......her initial thought is the finer grains might leek through and the seep may be too fast without paper. Preventing the finer grains getting through would require a coarser grind which would reduce some of the aroma/flavour in the final brew. For the darker roasts that is likely of less issue but for these very light roast beans the profile is influenced by even the most subtle changes. The filters she uses are again a Japanese brand which (supposedly) specifically do not impart any flavour.
If you get the chance to try some of the "Honey Process" beans particularly famous are the varieties in the "Musician Series" from Costa Rica. If you haven't experienced them it's actually quite a shock to know that the fruity/candy like flavours can be found in coffee.
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