Sumire Uesaka -- Nanatsu no Umi yori Kimi no Umi（七つの海よりキミの海）

Ahhh...yes. The inimitable seiyuu Sumire Uesaka（上坂すみれ）. Loves the former Soviet Union, gets easily creeped out by overly gooey compliments to her, and has some of the more extreme reactions that I've seen and heard from any celebrity on either side of the Pacific. Plus she's popped up on a lot of anime that my buddy has introduced to me over the years such as "Chūnibyō demo Koi ga Shitai!"（中二病でも恋がしたい!...Love, Chunibyo & Other Delusions）, but she's also been quite entertaining all by herself.

One day, I was rather curious about how she started out. Now, she did have her performance in the ending theme for Season 1 of the aforementioned "Chūnibyō demo Koi ga Shitai!" during its time in 2012, but her debut single as a solo performer came in April 2013 with "Nanatsu no Umi yori Kimi no Umi" (Your Sea More Than The Seven Seas).

Seeing a few of her music videos, she definitely has her own style but I think she really made a splash for the official video for this first single of hers. I recently watched some YouTube videos of Soviet-era television, and yes, perhaps the intro got some inspiration from that medium. And then the song launches into a carnival-like atmosphere of craziness that pulls in circus music, heavy metal and maybe even ska. Not sure whether the people around her had already figured her out but "Nanatsu" and the video certainly come across as pure Sumipe earworm.

https://www.nicovideo.jp/watch/sm20972022

Written by Aki Hata（畑亜貴）and composed by Satoru Kousaki（神前暁）, "Nanatsu" was also the opening theme song for the anime "Namiuchigiwa no Muromi-san"（波打際のむろみさん...Muromi of the Shore）which had a year-long run between 2013 and 2014. Uesaka herself also had a role in there as a buddy mermaid with a love of booze.