Ok, even though I am an expert at this fishing, I have a small problem. I am currently at the last fishing quest and in need for the last fish: The Ninja Fish. Oddly The fish was never there after I visit Tatakai Outpost many times and went to that only river where the fish is, and even though there were ice fish and grape jellyfish (rank 2 storm), the ice fish was only rank one and there were no rank 2 ice fish, so there were only dekois and icecudas. I spent a lot of energy casting these spells: Reveal fish rank 1, Charm fish, Summon fish, Reveal fish school, and winnow ice fish. and After casting all of those so I would know which fish is rank 2, apparently, there were no rank 2 fish there. I fixed my solution by heading to another place where the fish might be (at least the wiki says) the fish can also be found in "Ice house" and Kembaalung Village. But I still wanted to get that word out there about the missing fish
I fish for the ninja fish at an ice house or at Kembalung Village. I have caught the fish at both places. I never tried for it at Tatakai Outpost. It swims faster than the other fish in the 2 areas I mentioned and is a smaller fish. It is an ice fish level 2. The ninja fish is also very evasive so one has to literally chase him. Don't give up! It's a cool looking fish.
At Kembaalung, it is usually on the right side as one looks to the waterfall. If you cast your lure and the fish darts the other way then that's the ninja. Go after it. Eventually you'll hook it.
At an ice house although they are all over, I usually can catch one quickly on the right side of the iceberg path crossing to the castle/house. Scan the waters. If you see a fast moving fish, cast ice level 2.