Are they saying the correct asnwer is this?

I just want to understand.

the only thing we know so far is that we should write the main name (first and last, if there is) of the character when we are guessing. whats inside the parenthesis is not something we should add.

Kakuzu was the only correct answer.

kakuzu is lowercase and is incorrect (mentioned by support).

Anything with [] is incorrect as no clues point towards a specific tag (also mentioned by support).

Anything other than "Kakuzu" is incorrect. If you put anything other than EXACTLY that, you are incorrect.

is there no appeal? this is a guessing competition. and there is no other character we are referring to its just like lazy coding. this is unfair. isnt there anyone that can solve this? there isnt even any rules just plain text when you predict. and they're being strict isnt healthy. i would understand if there was another character we are refering to with similar name. but theres only one kakuzu. it worked in previous mystery ninjas. idk.

Unfortunately capitalization matters and you could have used your multiple attempts to ensure any iteration worked.