she is a Japanese vs she is Japanese

Some examples from the web:

• She is a perfect and pure Japanese girl
• He joined a Japanese dating site.
• A Japanese sneaker company is renting out this warehouse.
• Most Europeans cannot tell a Japanese from a Chinese.
• Swinging lifeless on a Japanese maple.
• My colleague, a Japanese teacher.
• Hilda and Jo Survived a Japanese prison camp.
• A Japanese Death List has been exposed.
• A Japanese funeral would've cost a fortune.
• Met a Japanese girl at the art museum.
• Methedrine was first distilled by a Japanese scientist before WWll.
• We ran into a Japanese patrol.
• I don't ever recall receiving the fortune cookie in a Japanese restaurant.
• He is a Japanese Kendo expert.
• We used both an Italian architect and a Japanese architect.
• It's a Japanese stone garden.
• The tire was stabbed by a Japanese garden knife.
• I have a Japanese client, just like you.
• This will never be like a Japanese factory, jack.
• Maybe he's just got a Japanese vibe about him.

Some examples from the web:

• Mine is Japanese version, too.
• Kuruma is Japanese for car, ziva.
• Mr. Kaji is Japanese, and I'm Chinese.
• This is Japanese kanji for "self".
• One is Japanese and the other is Italian.
• Mr Suzuki is Japanese, and therefore a human being.
• That is Japanese for California roll.
• A little, his boss is Japanese.
• Your mother is Japanese which means you have some Japanese blood.
• That is Japanese for California Roll.
• Is Japanese taught in your school now?
• Because the dollar took a dive against the yen and it turns out his client is Japanese.
• Saraka is Japanese but was born in San Francisco.
• That one barely grazed me, because I'm Korean, and Pikachu is Japanese.
• This is German, and this is Japanese, they're good.
• The interesting question is: How do you go from fortune cookies being something that is Japanese to being something that is Chinese? Well, we locked up all the Japanese during World War II, including those that made fortune cookies.
• Even Japanese can make mistakes when they speak Japanese.
• The Japanese say no director is more Japanese than Ozu.
• The Japanese embassy has warned Japanese citizens to be careful.
• Any Japanese in a foreign country must surely miss Japanese food.