Sora was engaged to Ryousuke but later fell in love with Tokio. She let Tokio paint her in her most beautiful form, i.e. naked.
It is later revealed that Sora is pregnant with Tokio's child. However, at this moment, Tokio is engrossed with zero-time and doesn't not pay much attention to Sora. When Ryousuke tells her this, he gives Sora his pocket watch. Soon after, Sora leaves the island.