It was his younger sister who confessed to him. He thought it must be some kind of lapse in judgment, but one night, she came to his bed. He could have brushed it off, but he thought that if he comforted her once, she would calm down... But he was wrong. She had extraordinary large breasts and she loved him. He had only intended to comfort her, but he found himself unable to suppress the excitement that was building up inside him... On another day, they continued to seek each other out at every opportunity, and their relationship gradually became more intense. Unable to contain their excitement and afraid of being found out, the two made a promise to each other, "We will only have sex on rainy days when the sound can be drowned out..." Original: JACK-POT A live-action adaptation of Jura's pure love story! A collaboration with a popular doujin work! Click here for the original doujin work "RAIN - It was my sister who confessed to me"!