Sadly, I have heard of
Hachi only for its cancellation so I waited for FWPA to translate the last chapters before reading it (and thank you for your hard work). So, I just finished it: it isn't a bad manga but neither it is special as
JW3 was.
I noticed that Masuda's art is greatly improved: I mean, some tables in the last part of
JW3 were beautiful but here he has reached another level. Also, I'm delighted he hasn't lost his touch for eldritch horror: yes, I'm talking about the eye in ch. 31.
Also (almost) all of the cast was enjoyable and the relationships between the characters were managed really well (as I would expect from the author) despite the few time to make them grow.
So... what didn't work? I don't know for myself, like gathering good ingredients and making a not so good dish. Personally, I wasn't too interested in the overall plot (but maybe it was me: I don't like manga about aspiring or professional mangaka) and I found the start and the E-rank rather annoying.
Anyway, I wish Masuda more luck for his next work: IMHO he is a really good author... he just has to find the right story to make his talent shine. Personally, I would love reading a supernatural/horror manga by him... even if I'm still waiting for
Momobutttarou XD