Yume Tagai

Yume Tagai is a traditional Yume Nikki fangame. The game's first act is centered around Makitsuki, a girl living in a small abandoned room who cannot leave.
Upon accomplishing a series of tasks, Sakiyuk becomes a playable character. From this point onwards, you can alternate between her and Makitsuki by waking up, with the dream world's bedroom being the main area.