These are two very sweet shoujo love stories, both featuring a slightly corny school-based plot. They also have a cute, kind-hearted bishie love interests that looks like a delinquent. While Rensou Mode is much more shallow and comedy-based (but still cute), Honey is adorable and pure, and developing well at this point. Rensou Mode is a oneshot (meaning less development); Honey is an ongoing manga that came from a oneshot called Sugar/Granulated Sugar.
Similar premise, both males who look scary confessing to a girl who is scared of them. Kare to Watashi has borderline smut scenes though, while Honey carries a lighter tone. Both are good reads but stay away if your preferences don't involve smut.