Welcome to Citrus Sweet, the FIRST ENGLISH website dedicated to Yeo Ho-Kyung's popular series: Vitamin! No, it's not manga. Not even remotely Japanese. But it IS 'manhwa', which is 'cartoon' in Korean.
Korean manhwa is NOT a rip-off of Japanese manga. The two countries, being so close together, do share a lot of aspects (appearance, history, foods, vocabulary, etymology, etc.). So it can't be helped that some Korean artwork look a lot like Japanese art.
Is this too much newness for you to handle?? Don't worry--Korean manhwa is EXTREMELY obscure within American society. My mission? To someday have people in America, and perhaps around the world, to enjoy Korean manhwa as much as they do Japanese manga.