Sono Yubi Dake ga Shitteiru vo

It's ultimate expression of love ­­– to wear matching rings with your significant other, showing the world that you are a couple. High school student, Wataru Fujii, also wears one though he is single. When he accidentally switches rings with popular and handsome senior, Yuichi Kazuki, they discover that their rings pair up! Since then, Kazuki, who is known for being kind to all becomes strangely harsh to Wataru. They alternate between hot and cold, as inbetween clashes they begin to sort their feelings for one another. Are Wataru and Kazuki the worst of enemies or are they actually soulmates?