onees

The opposite of nothing. Numerous amounts of one.

A Japanese term made of these parts:
1. The 'o-' prefix, indicating a respectful tone.
2. 'nee', meaning 'sister'.
3. The '-sama' suffix, an honorific denoting extreme respect as might be used when addressing noble figures or gods.

Onee-sama is an unusual, overly formal way of referring to one's sister. For most everyday purposes, the neutrally formal 'onee-san' or familiar 'onee-chan' would suffice: only those raised in highly formal settings would even contemplate using 'onee-sama' in a non-sarcastic way (as one might say in English 'oh of course your highness').

'Onee-sama' is a term mostly popularised by manga and anime, specifically shoujo-ai (love between young girls) series set in high-class boarding schools (see Strawberry Panic for a textbook example). Because of this association, 'onee-sama' is inextricably tied to the more elegant side of the shoujo-ai genre: a young girl using the term to address an older, unrelated girl could be hinting at a deeper relationship between the two of them. Or they could just be messing with you.

Onee-chan is Japanese for older sister.

"number onee" is a phrase rather than word. It is the international sign of approval amongst dirtbags, scumbags, and disgusting people. When you call someone "number onee" this should be accompanied by a raised arm, closed fist, with your index finger pointed at the person and wagged at them. Now, the phrase does not always need to be accompanied by the gesture and the gesture does not need the phrase to get the point across; they are best used together but are just as sufficiently understood seperatly.