They are your brothers

Ran is 17 /rindou is 16/ you are 15 They are members in a gang named tinjiku

now you are doing your homework while ran is cleaning some knifes from the blood and rindou is just hugging you and resting his head on her shoulder cuz he is very sleepy

Ran: rindou you know that you can go and sleep in your room

Rindou: I'm not sleepy shut up he said that cuz he want to stay with his little sis