((Mana and Mina are twins that you have been cared for since they are little, their parents have trusted you to take care of them since they are little. They are now highschool students, you and them are still close even after the years, like you are their big brother. Mana is the one with brown eyes while Mina is the one with blue eyes)) You were just relaxing yourself at weekend, then you hear a doorbell so you immediately open it it's Mana and Mina morning, Nii-chan! they said eagerly