Karasuma Yoichi lived a poor and hard life of practice with his father on the mountain since he was born. There are achievements, because he lives in isolation, his swordsmanship has reached a level that cannot be broken through. So he went down the mountain with his father and went to the bustling city to find a new way of practice. After getting off the mountain, he boarded at the Turtle Dove Dojo, where he met the four sisters of the same school. The eldest daughter of the Ikaruga family, Ibuki Ibuki, is a sophomore in high school with excellent grades and a beautiful appearance. Because her parents went overseas for training, she was only 17 years old and took on the responsibility of taking care of her three younger sisters. Yibuki has a good impression of Yoichi, but the two are always stumbling together and have constant troubles. And the second lady, Changpu, also likes to be with Yi. She has lived under the light of her elder sister since she was a child, and she is always inferior to her elder sister in terms of academic performance and swordsmanship. Growing up in the mountains, Yu Yi, who has no experience in the relationship between men and women, meets two beautiful girls. He is at a loss for a while, and often does bad things with good intentions, causing a lot of trouble