About 4 years before Koji Kikkawa（吉川晃司） teamed up with Tomoyasu Hotei（布袋寅泰） of BOOWY to start the duo of COMPLEX, he launched a solo career in 1984. And just like with COMPLEX, his debut single as a solo singer started off with a bang. To be honest, "Monica" is the only Kikkawa song I know. I first heard it at karaoke and then came the appearances on all of those music shows on Japanese TV, and then I even heard Leslie Cheung's cover of it when I was doing one of my frequent record-searching hunts at Wah Yueh downtown.
Now that I've heard a fair bit of Motoharu Sano（佐野元春） thanks to nikala's articles, I think Kikkawa sounds somewhat like him (at least in this song) especially with his choice of genre. However, Kikkawa, as you can see in his appearance above, is more powerfully built. Making my link with the Olympics currently happening in Sochi, Russia, according to the Wikipedia article on him, he was supposed to have been on the Japanese water polo team in the Olympics (presumably the LA Games), but decided to go for the mike instead of the Gold. Still, his training for the sport certainly showed up in those wide-as-a-highway shoulders which certainly helped in gaining a lot of lovestruck fans.
It looks like Kikkawa won the bet as "Monica" became a big hit. Written by Yoshiko Miura（三浦徳子）and composed by the band NOBODY, it was released in February 1984 and reached as high as No. 4 on the Oricon weeklies. The song also won him a Best Newcomer Prize at the annual Japan Record Awards. Eventually, "Monica" would become the 23rd-ranked song of the year. The song also got onto Kikkawa's debut album, "Parachute ga Ochita Natsu" （パラシュートが落ちた夏...The Summer The Parachute Fell）.
Here is the Leslie Cheung cover.