Keirin Yarou: Shuu to Kazumi no Love Story

After Kazumi was betrayed by her fiancé, she goes on a matchmaking date in response. There she meets Shuu, a professional cyclist, who had also been dumped by his girlfriend. They decide to get married to spite their former lovers. But as she learns more about Shuu and about cycling, Kazumi develops a deep love for both. Shuu lives in a world of tough competition, and Kazumi will do anything to support him in loving harmony! A long-running and very popular series!

(Source: Shogakukan, translated)