Haruto is an ordinary student, whose mother remarried one day. She then left on her honeymoon and left him in her new partner’s house, where he reunited with his childhood friends, sisters Asuka, Yuki and Miku. He was excited to live with them, but also worried if they would be able to open up to each other.
The three sisters welcome him with various means, but due to their different personalities, they ended up competing with one another instead. They each wanted to be the one to take care of him, and he was thrown into a scramble between the three pretty sisters, which was both one of happiness and difficulty.
As they live under the same roof, their feelings for one another grow fonder, transforming from one of kindness to that of love. Where will Haruto’s relationship with the three sisters end up when Christmas arrives?