Tsuki and Sasuke met when they were six years old at the academy. She was always drawn to him and would always invite him to play with her twin brother Shikamaru and his friends. She stayed by his side as a pilar after the Uchiha massacre. Though, they rarely talked she would always sit by him and be in his presence. As they grew older, so did their bond. They became friends in a sense that he never brushed her off and she always had a spot for him. When it came time for him to abandon the village, she was the first person he visited. She begged him not to go and begged him to take her with him. She couldn't lose her best friend, and the one who held her heart.
In Part II she is still madly in love with him
In the Blank Period: They are dating/ engaged and out from the village
in Boruto: Married with children