I am male and my breasts feel like it hard around my nipple and is very sensitive in one of them.

Gynecomastia? Probably this is nothing serious. Gynecomastia is female type breast development in males. Mild gynecomastia, including firm tenderness under the nipple, is a fairly common symptom of puberty in young men. This might be most likely if your own puberty was on the late side. But if this persists more than a few weeks, best to see a doctor, preferably an endocrinologist.