A Koi Fish is a man who gets overly attached to a girl and refuse to leave her alone when she has no interest in him. They generally become psychotic and ruin their friendships because of this. Some of them try to ruin their targets lives.
Girl1:"This guy won't leave me alone and just doesn't stop trying to ruin my life"#
Girl2:"ClassicKoi Fish"
In Japan during world war II a group of homosexuals got the Koi Fish tattoo on their left arm. Now commonly used in Japan and America as a more verbose way of letting people know their sexual orientation.
Person 1: "My friend just got a Koi Fish Tattoo on his arm."
Person 2: "So how long have you known?"
Person 1: "He has been out of the closet for a couple years now."
Person 2: "Good for him."
While being cracked out of your mind yet still performing. Similar to how a koi fish swim in a small pond cracked out of its mind but still performing.
Deceiving someone via social media or dating site by posting/sending pics or videos that are very old and
don't represent the way you currently look.
Koi's are the longest living fish. They have been reported to achieve ages of 100–200 years. - Wikipedia
Fuck man I got koifished on POF. That chick I met the other night looked hot on her profile pics, but when I saw her she looked 15 years older and had gained alot of weight.