onii chan definition
Best Answer: It's Japanese. Onii-chan means older brother. It can also be used with the suffixes. '-san-'. 'sama'. if the brother is much older, or very honored/respected. Onee-chan means older sister. It can also be used with the same suffixes I put above, if respected/honored or much older. '-chan' symbolizes a much closer bond between the siblings, hence the lack of formality. Onii is pronounced as OH-nee, while Onii is pronounced as OH-nay.