Ocha Nigosu really fits your title. Masaya Funebashi is a bit naive and misunderstood
Well, unfortunately, the series is a manga and not romance* though. Well, you can probably just take a peek. Only the first 16 chapters were translated. You won't get that much attached to this series, but it's not a total waste to read since it has some hints of comedy.
For anime, I can only think of Hanamichi Sakuragi of
Slam Dunk this time. The guy is a deliquent, but tried basketball to win over a girl. Though from what I remembered about the series, it's more sports than romance...