Dear Moonbeam,(Masato and Fionn)...

I think the version you are looking for, is this one :

Trees they grow high, and the leaves they do grow green
Many is the time my true love I've seen
Many an hour I've watched him all alone
He's young but he's daily growin'.

Father, dear father, you've done me great wrong
You've married me to a boy who is too young
I'm twice twelve and he is but fourteen
He's young but he's daily growin'.

Daughter, dear daughter, I've done you no wrong
I've married you to a great lord's son
He'll be a man to you when I'm dead and gone
He's young but he's daily growin'.

Father, dear father, if you see fit
We'll send my love to college for one year yet
Tie blue ribbons all around his head
To let the ladies know that he's married.

One day I was looking o'er my father's castle wall
I saw all the boys a-playing at the ball
My own true love was the flower of them all
He's young but he's daily growin'.

The age of fourteen, he was a married man
Age of fifteen, the father of a son
Age of sixteen, on his grave the grass was green
Cruel Death had put an end to his growin'.

I'll make my love a shroud of the holland so fine
Every stitch I put in it, the tears come tricklin' down
Once I had a true love, but now I've ne'er one
But I'll watch o'er his son while he's growin'.

---

Line breaks - <br> - added. --JoeClone