Yes, nothing like a rich and smooth slice of cheesecake with a hot cup of coffee in a stylish cafe. I do have a soft spot for Timmies here but sometimes I miss those much more prolific mom-&-pop coffeehouses in Japan.
When I was first trying to search for some information on this singer Mizuki Koyama, I went with the kanji「小山美月」that had been served on the above video. Couldn't find a thing about her online and so I had presumed that an unfortunate precedent was about to be set. However, thankfully, she does have an entry in my "Japanese City Pop" and found out that her kanji is actually「小山水城」. In fact, she's even represented in J-Wiki.
Born and raised in Gifu Prefecture, Koyama had studied piano from a young age and got some education in classical music, pop and enka. She later attended Sophia University in Tokyo and during that time, she got into the swing (no pun intended) of things with jazz piano and vocal. Impressed by the works of Barbra Streisand, she apprenticed under artists such as singer Yurie Kokubu（国分友里恵）and songwriter Yusuke Honma（本間勇輔）. According to her J-Wiki bio, she also loves people such as Sam Cooke, Diana Krall and Quincy Jones.
In 1985, she released her first album "Angel's dream" and from it, here is "River Side Cafe", a mellow and indeed cafe-friendly urban contemporary number that was at least composed by Yasuhiro Abe（安部恭弘）. I couldn't pin down who had taken care of the lyrics although it could have been Koyama or Abe. I do love that trombone solo in the middle and the dawn/dusk breeziness of it all (Daemonskald rescue: The lyricist is Kei or Megumi Yokoyama/横山恵).
Just for pure trivia purposes, her elder son happens to be a professional soccer player for Giravanz Kitakyushu, Akira Disaro（ディサロ 燦）. Along with her singing and songwriting, Koyama is also a vocal trainer and vocal arranger.