The Tender-hearted Prince pretty much pun on 어린 (little/young) and 여린 (tender-hearted/sentimental)

Why are you here all alone?

Leave me alone, nobody welcomes me except you.

I'm not as weak as a human, so I can wander alone.

Hmm... Yes, I am pretty weak.

My heart that is... It's hard to see a maiden wander alone,

So won't you come with me?