As a fellow owner of the Hario Neldrip Bloom with some level of Japanese language knowledge, I will try to help out.
The basic operation of the device is pretty straight-forward (i.e., it is a pourover filter device, just with a cloth filter). The only instruction in the manual that I recall as being non-obvious was to store the cloth filter in the refrigerator in an air-tight container filled with clean water. This does seem to have some effect in terms of reducing the residual coffee smell on the filter between "heavy-duty" cleaning sessions.
As far as cleaning goes: after each session, I thoroughly rinse the filter in clean water and refill the storage container with fresh water before returning it to the fridge. Every two days or so, I boil the cloth filter in water; every week or two, I boil it in a cleaning solution of water with a tiny bit of Cafiza (and then rinse thoroughly). This schedule is adapted/synthesized from various Japanese websites and seems to work well enough.
I also found some videos online which give some possible techniques for the actual pour (
this is a particularly interesting one, although the extraction timings shown in the video are much longer than what works for me). A search in Google (or Google video) for ネルドリップ ("Neldrip") or ドリップ コーヒー ("drip coffee") gives other ideas; the product does seem to be fairly popular in Japan, as there is quite a bit of (Japanese language) information available about it on the web.
That is all I can think of right now; maybe someone with more experience has more to say.
Navin