Zettai Ryouiki (絶対領域) is the perfect ratio of skin, skirt, and sock that generates intense cuteness. Mathematically, the ratio is 4:1:2.5 (length of mini-skirt : the skin shown : length of socks above knee) with +/-25% error. Zettai Ryouiki is broken into grades with class A and B being true Zettai Ryouiki.  
 
[fetish day]