I don't mind your grammar, but I'm studying to be an English teacher, so let me see if I can practice by helping you.
When you are talking about one person or thing (except “you”), use “is” not “are.”
is=one thing
are=more than one thing
The “is/are” goes before what you're talking about. So
“Why IS *Mirai* so stupid?” (1 person)
“Why ARE *they* fighting?” (2 people)
“Why IS *the money* on the floor?” (1 thing)
“Why ARE *his clothes* wet?” (More than 1 thing)
What's about is what you do when you are asking WHY Questions. If you are saying something, the IS/ARE goes before what you're talking about:
“*Mirai* IS so stupid.”
PRACTICE
Do we use ARE or IS in this sentence:
“Why ____ *the uke* so stupid?”
Where does the ARE go in the sentence? Before or After *the boyfriends*?:
“Why ____ the boyfriends ____ so mean?”
Now practice by turning the sentence saying something to a Why Question:
“*Mirai* IS in love.”
Why mirai are so stupid
I hate this uke
Its make me pissed off ( ̄へ ̄)
(Sorry if wrong grammar)