At first Tadase started getting feelings for Amulet Heart because she was so outgoing and shined and he has never seen a girl like that before, he only liked Amulet Heart even though Amulet Heart was part of Amu. Later he finally relized that Amulet Heart is part of Amu and thats when he starting having feelings for Amu and confessed that he loved her. Now he likes Amu for Amu, not her Amulet Heart side. Amu is happy that Tadase likes her but recently she has shown to have less romantic feelings for him. In the manga she relized that shes in love with Ikuto and only liked Tadase’s outer character and now she doesnt like Tadase like that anymore, she loves Ikuto. Tadase loves her but he already knew Amu had feelings for Ikuto and that Ikuto loves her for a while now and pretty much gave up on trying to win her over and let Ikuto have her. He still loves her though.