If it is a genre, it's a very very sub sub one - I got one result looking for books in that category
So, Tizio, in addition to what's been said above, figuring out who repped similar books, if your book got into bookshops, where would it be shelved? Under what broad genre (that this zen fiction is a sub part of)? Just because it involves zen*, might not make it 'zen fiction', then again it might. But you need to knwo what broader area you're looking at.
*For instance, Lord of Light involves Buddhism, but isn't classed as 'Buddhist fiction', it's shelved under SFF