It's been nice discovering some of these literally groovy bands recently such as microstar and Blue Peppers. And thanks to commenter Matt Gallais for that latter band, I was informed of another such group.
Formed in 2000, the J-Wiki article about the band Lamp is that they are known for some "...complex yet refined sounds" ultimately based on bossa nova. Taiyo Someya（染谷大陽）, Yusuke Nagai（永井祐介）and Kaori Sakakibara（榊原香保里）all have a hand in the creation of the songs and are multi-instrumentalists.
Matt was kind enough to introduce this Lamp tune called "A Toshi no Aki". Not sure whether the translation is "The Autumn of City A" or, taking into consideration that the first letter may indeed be acting as an indefinite article, it is actually "A City's Autumn". In any case, it's a fascinating song since I get that flavour of Ringo Shiina（椎名林檎）especially in the opening/ending and Sakakibara's vocals, while the overall arrangement reminds me of some of the work of Misia and Bird. There may be that bossa nova as the foundation but there's much more overlaying it whether it be smooth jazz or R&B.
"A Toshi no Aki" is the second track of Lamp's 7th album "Yume"（ゆめ...Dreams）from February 2014. So far, the band has come up with 8 albums.