This is 'Hi', sad. The lower piece (shin) is a stylized image of a heart, figuratively feelings/thoughts/mind.
The top (also called hi) is a stylized image of wings, from a pictograph of a bird spreading wings to fly off. It originally meant 'to fly away from' and came to mean 'turn away from', 'seperate' and 'not'.
This character exemplifies a lot of what I find fascinating about studying kanji etymology. It's a pun, but a very poetic one. The wing-image is used because it has the same sound as the concept in question ("hi"), because alone it conveys the concept 'not'. But also because it conveys seperation/loss/distance and opening/rending and freedom/flight. Meanings within meanings.
And it doesn't hurt that the kanji itself is very beautiful in form.