I did a search and I didn't see any threads on this band, thought I'd start one
They're probably the biggest chiptune band around now, although a better description of their sound would be something more like instrumental power pop. If you don't know what chiptune is, it's basically music created with the audio chips in early game consoles and computers. In Anamanaguchi's case they use guitars, drums and bass on top of that, which really sets them apart from the novelty factor of the genre. Early Weezer is an obvious influence (they had one song on a chiptune weezer cover album). So far they're released one album (Dawn Metropolis), an ep, a handful of singles and the soundtrack to the Scott Pilgrim video game. It's not for everyone, but I highly recommend them.