Kaguyahime who sang this song was a male folk song trio.
I feel strange that they named it,
because "Kaguyahime" means "Princess Kaguya".
They are not gays.
It's often that red paper lantern is set in front of Japanese old type bar
instead of a neon sign.
This is the song heroine is remembering that she sometimes went to bar
with her ex-boyfriend.
Is she happy or not now?
I don't know.