You are a Four Leaf Clover

Kimi wa Yotsuba no Cloverorijinal adı

Uichi, once a happy and popular boy, is now the victim of cruel bullying. Then suddenly Yotsuba, his childhood friend and first love, shows up. How will this cute and kind-hearted girl try to help him...? (Source: Weekly Shonen Champion, translated) Note: Includes 1 extra chapter