Wow, I can't believe it's been a year since Mognet's first Karaoke PV release! We're celebrating today with one of my favourite songs.
The Boom's "Shima Uta" is quite the classic song, it's so popular it even inspired its own genre! Anyway, the shima uta is a very okinawan style of music, combining traditional Okinawan music and beats with more pop-influenced songwriting.

Even better (or worse, depending on your demeanor) is what this song and PV represent. It's meant as a tribute to Okinawa, and honors the people from there who died in the battles of World War II. The battles raged on Okinawa are considered a separate thing from the rest of the mainland by historians, because Okinawa was the only place during the whole of WW II to have actual battles on land.

Especially something you want to note are the lines,
"I met you in the forest of Uuji
And under the Uuji tree, I say goodbye to you forever"

Uuji is sugarcane. The reason why it's "under the Uuji tree, I say goodbye to you forever," is because the civilian families would hide inside the sugarcane fields from the American forces, and the Okinawan soldiers, with their wives, children, girlfriends in the fields, would have to burn the fields so that information would not be leaked to the American soldiers.
I think you'll really enjoy this one, or at least find it as touching as I did.