Heard this on the Sirius 60s channel. Quite a pretty song. This was the other Liverpool band managed by Brian Epstein. Gerry Marsden was a very under-appreciated singer.
I just discovered them a week or two ago, myself. They are very pleasant to listen to.
As for me, I just listened to this like three times in a row, also completely new to me as of a few days ago. It's pretty much the most adorable and heart-warming thing I have ever seen or heard, although I know nothing of the anime it came from, or who these singers are =>