So nice to come across a "new" band that you can really get into. The more I listen to Sakanaction (サカナクション), the more I like them. "Shin Takarajima" (新宝島, New Treasure Island) is the first song on their best-of album "Book of Fish" (魚図鑑, Sakana Zukan).
This video is so dasai (uncool) it's truly a wonderful thing to behold.
The music reminds me of a number of bands and artists that I have liked over the years. The first notes on the synth are like something from a Japanese-themed movie in the '80s--think Karate Kid or Black Rain--with hints of Vangelis's China album. Lead singer Yamaguchi Ichirō's reminds me somewhat of Kururi front man Gishida Shigeru's. There are some similarities, too, with a few songs by Shiina Ringo, particularly on the song "Yoru no Odoriko". See video below.
I've listened to the whole 36-song album a few times already and there aren't any duds on it. ¥2,800 well spent.