if she had been away on a trip for three days, then she'd become sefre with her sister next door... tachibana mary.

She was having an affair with her friend. It was Mary, the novelist who lived in the room next to her, who spoke to the stinging hajime. They had sex as Mary said, "I'll comfort you." The distance between the two is rapidly shrinking in three days from her flirtation trip to her return. Conversation like a lover, sex like a lover. But the two worlds are separated by doors. Another life that could have been different if one choice was different. There are so many options for her – Parallel World (Multiverse) x Tachibana Mary, finally opening.