Sara Sara Sasara

One day, the main character gets involved in a mission to save God due to some reasons. To save God, he needs to unite with miko both physically and mentally in his dream using the power given from God and strengthens bonds with them. Of course, he can do anything he wants in his dream.... At a different place in a different costume...? He strengthens the bonds with miko like this, but the bonds that only exist in his dream gradually affect his real life...?