Trasparente means "transparent". While it might seem like a common word, its use here is quite striking and sets the tone for the entire song.
The lyrics describe someone who is "trasparente, sin un as bajo la manga" (transparent, without an ace up their sleeve), meaning they are open, honest, and have nothing to hide. This contrasts beautifully with the singer's initial guardedness, making it a pivotal word in the narrative of falling in love.
"A Un Beso" is about someone who swore they would never fall in love again, only to be won over completely by one kiss. The singer describes herself as guarded and untouchable, warning her partner from the start that she does not fall for people, yet he breaks through anyway.
That single kiss changes everything. She admits she was ready to give up on love, never expecting to end up surrendering so fully. What started as fear of commitment turns into picturing an entire future together, a home, a family, all because of one person she did not plan for.
The song captures that moment of losing control to love despite every intention to stay closed off, and choosing to embrace it rather than fight it.