Is it a forbidden love or not? Touya, the older twin brother, gets into a fight with his younger sister, Maasa, over a trivial matter and runs away from home. When he casually goes to the rooftop of the condominium, he finds his friend Kazuma, who is also a twin, sitting there. The two talk about each others home situation and envy each other. I wish our sisters could swap. The two boys throw those words into the night sky. - Eight years later, Touya and Kazumas relationship is still the same as it has always been. Except for one point... I like you Touya, Touya sighs at the words spoken by Maasa. This is the beginning of a story of crossed twins, where their feelings and perseptions cross.