Does my character seem like a real person?

Sounds like a typical American.

No. You have lots of details, very interesting details. To make her seem real, you have to breathe life into her. You can have all the bizarre or reality based details you can think of, but that won’t make anyone real. Putting strings on a puppet won’t make it dance. Someone has to take the other end of the strings and know what to do with them.
Look at your details, and decide what you can do with them to give her life and make her real.

Kari and Mari??

Not yet. You are telling, not showing. So far, it’s a shopping list.

I agree with the general consensus. The character has traits, and it’s not that I’m asking to read or see the whole story or whichever. I’m guessing this is in early stages anyway, but thing is, we haven’t seen her act or do anything. So I can’t say. It’s easy to make up characters, it’s another thing to give them life.

One thing puzzles me though. Mari is the sister who looks Japanese, while Kari looks more Caucasian. So nobody believes that Kari is Japanese because of her looks, but as I understand, even though both girls are neglected by their parents, they live with them? So why does no one believe that Kari is Japanese, if she has one Japanese mom, and a little sister who obviously looks Japanese? Unless something in the story prevents most people around Kari to see her parents, or her sister.

Yes, but as others are saying, there is too much description of the characters. Tell their story, not what they look and act like.
And also, why does nobody believe that she is Japanese? She speaks the language fluently and her sister looks like she is from Japan. Unless this has something to do with the plot, I say take it out.
The names Kari and Mari are a little bit…different, but this is still believable because some parents rhyme their kids’ names.

Interestingly enough, I looked up the name ’‘Hikari’’ and it seems to mean light in Japanese. It’s also the name of like three brand companies in Japan.

She’s kind of pinging my radar as a Mary Sue. Most of your description is about your character’s looks, her interests, and her background, but there’s very little about her personality. If you aren’t familiar with Mary Sues, the best way I can explain it is that it’s a character who is the special darling of her creator. These characters often have cool backstories, exotic/ attractive looks, magical powers, nifty pets, etc. They often have unique abilities that their peers don’t have. Many of them are morally righteous, but treated unfairly by the people around them, so that the reader will sympathize with this character.

A common thread is that they have many cool and unique qualities that don’t have anything to do with personality.

There’s no one universal definition; it’s mostly a know it when you see it kind of thing. You get the sense that this character is extra-special in the mind of his/her creator, and that the author really, really wants you to feel the same way. Basically, the character is a vehicle for the author’s daydreams.

It’s not necessarily a bad thing to write characters like this, as long as you back it up with an interesting personality. If you do it right, you get Batman. If you do it wrong, you get Bella from Twilight.

What really makes a character compelling is their personality. One of my favorite fictional characters these days is Nick from The New Girl. He’s a schlubby, underachieving 30-something who covers his pessimism with sarcastic, self-effacing humor. The show gets a lot of humor out of all the unintentionally silly things he does and his grumpy, curmudgeony attidude. (In other words, the writers gave him realistic flaws.) And underneath all that, he’s a good guy. You would never WANT to be Nick, but as a character, he’s entertaining, endearing, and you can relate to him.

When you’re building a character, start with the personality and try to see her the way the rest of the world would see her. It’s important not to treat your character, in the narrative, as though she’s always right. Try to understand the viewpoints of everyone in the story (for instance, the parents.)

You mentioned that your character is tomboyish, and that’s a nice starting point. Maybe she’s also rude, and it’s always getting her into (justified) trouble. But maybe she’s also brave and strong… until one day, she takes on a situation that she can’d handle on her own. Etc. In real life, people have a mix of qualities, and sometimes they contradict themselves. When a character surprises you, that’s when things get interesting.