Miju (Grandmaster Blood Scribe) is a tortollan located on a small island south-west of Xibala in Zuldazar. Nearby this mysterious NPC there is an empty area surrounded by 4 weird signs, which could be part of a secret that has yet to be uncovered.

/way Zandalar 42.5 87.6

Interacting with https://www.wowhead.com/npc=131397/miju:

Well you've certainly traveled far to visit me, young one.

I've several novels on the history of crabs, if that's something that peaks your interest?

Elrox#1939 pointed at several NPCs and items that might be related to Miju, but are not implemented yet:

Prydolin#3718 has documented similar signs throughout Kul Tiras and Zandalar, and NPCs that might be related to Miju: https://tinyurl.com/ycohtdtf

Mystery Status: Solved - 8.1.5 Content

BlizzCon 2018 Update: The items and NPCs above are related to the Tools of the Trade Questlines coming in Patch 8.1.5.