When it comes to the 1980s aidoru spectrum, Seiko Matsuda（松田聖子）was the cute burikko while Akina Nakamori（中森明菜）played the misunderstood rebel. However, Kyoko "Kyon-Kyon" Koizumi（小泉今日子）was somewhere in the middle...a basically decent kid with a cheeky streak and a gorgeous smile. She was probably the one in school that the shy girls wished they were although hanging out with her pretty much guaranteed a mandatory and not-so-happy visit to the teachers' room.
The above was a commercial that I saw on heavy rotation during my time in Gunma featuring an adult Kyon-Kyon still bringing that cheeky attitude into the working world as she tried to sell Knorr Soup while her superiors brooded away.
Single No. 29 for Koizumi was "Minogashitekure yo!" (Can't You Let It Go?) from March 1990 which sounds like Classic Kyon-Kyon. She plays the angelic devil or a devilish angel as the young cog who happily breaks a few rules such as eating a bento in the conference room (oh, the horror!), hogging the mike for 5 consecutive songs at karaoke, and eating desserts while on a diet. And most likely, she will be able to get away with all of that stuff (as mildly naughty as they are) with a wink and a smile and an ii jan（いいじゃん...aw, c'mon it's OK）.
"Minogashitekure yo!" hit No. 1 on Oricon and was the 43rd-ranked single of 1990. Hidehiko Kato（加藤英彦）of The Flying Kids provided the rock beat to the song while some unit called the Kappatsu Iinkai（活発委員会...The Active Committee）came up with the lyrics. Perhaps instant soup saw some success as well.