“My older sister and younger sister hate me.” Amachi Towa, a high school sophomore, has two beautiful sisters who are well known in the neighborhood. However, for some reason, both Arika (Older sister) and Sumika (Little sister) are cold to Towa. Every day he was supported by his childhood friend, Naruse Runa but…… [A new law has been enacted in Japan that allows siblings to marry each other] This news changed the relationship between the four. “I like you, To-kun.” “I love you, onii chan” Where did all the coldness go before?　They became full of possessiveness anytime, anywhere. In addition….. “Even though Towa is my Fiancee!” The sisters’ condition seems to have made Naruse Runa, the Fiancee and childhood friend of the sisters, who had been in an advantageous position until then, impatient… “Marry me, To-kun.” “Onii chan, please marry me.” “Towa, you’re going to marry me, right?” not dating, married!? This is a four-way romantic comedy between a cool older sister, a devilish younger sister, and the fiancee childhood friend. –I will have you this time, no matter how much I regret it.