Wake Up! We Are Brother and Sister

[Single heroine + no adoption relationship + deterioration of family ties + more daily life] Shen Bin, who went to war on behalf of his father, thought he would just show up as a representative like usual charity activities, but unexpectedly he got an unusual... Thing? Logically speaking, the intersection between them should have ended here, but-- "This little girl is so pitiful" "It's so fun to play with little girls." "Why is her brain so good?" "Sister, who studied this stuff? It's so cute." "The little girl is always talking about what she wants to do." "What does it mean that a couple is a lifelong family?" Xu Zhili did not expect that he would have some restless thoughts about his benefactor. But.... "If I'm not cheap, I'm also cheap to others." Besides, what if you ignore your own embarrassing... "Seduce"? "Aren't we in love with each other?" "Brother? It's just a nickname for tuning the piano," the girl said, lifting Shen Bin's chin.