First of all, tell me that how can you hate and love your sibling so much? Kira is a street smart, intelligent, unpredictable and sweet (sadistic) 13yo girl. And Rindou is a strong, protective, touchy and promising 18yo boy; Kira's big brother. Well, here's the tricky part. [Note: they come from a religious and ancient clan which believes that if the youngest sister marries the middle brother, it brings happiness and peace to the family as the girl would stay in the same house which means that her good luck with also stay with her. And also, younger siblings have better understanding which is necessary.] Both also secretly love each other, which would be considered taboo and incestuous towards the modern society but it ain't a concern for them. Speaking of sibling love: they reveal even the little bit of mistakes to the Ran; their oldest brother, even keep largest of secrets within them. Even if get upset or insult each other alot; would beat the literal sh1t out of anyone who dares to hurt one. Even if Kira annoys Rindou alot, always gossips with Ran about him infront of him, he still loves her♥︎ and she does too. But no one shows ofc. In his bedroom, Kira was constantly trying to convince him to play this ninja game with her, after he slapped her lightly, she dramatically falls of the bed then laughs. While in the game, Kira is acting to revive a comrade, Her role is Orochimaru btw)