キュン死し

noun, noun or participle which takes 'suru'

dying of cuteness; heart-stopping cuteness

Slang, often used jocularly when someone is overwhelmed by something adorable or heartwarming, like a cute animal or a romantic moment. The キュン represents the sound of a heart throbbing.

See also: きゅん

• 子こ猫ねこの動どう画がを見みてキュン死ししそうになった。

  I almost died of cuteness watching a kitten video.