1 definition by Superior Jacob

A Koi is someone who exceeds far beyond the pinnacle of being a simp.
Someone who is Koi will give their partner everything, they will do anything possible for any sort of attention, in which most cases are virtual.

The Koi is also someone who cannot fight back, but far more superior then simp, as a simp would run away and leave the girl to her own death, but a Koi will pretend no one else in the world exists except the partner.

A Koi will most likely enjoy constant sexual behaviour and or entering furry type behaviour.
*in the video game of vrchat*
Koi: "I love you so much you mean the world to me"
Her: "You do too"
*they are both lying down virtually, she is a little girl character bouncing up and down on his virtual wolf furry characters penis*
Random: "Ew, stop being a simp idiot"
*Koi mutes the Random so he cannot hear the Random yell at him, but can say what he likes without consequence as the random can still hear him*
Koi: "You are a di*k and no one loves you haaha"
Girl: "You are so smart and cool *hehe*"
Random: "Jesus... You are such a Koi"
by Superior Jacob April 3, 2020
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