You and Sanemi's mothers were best friends since they were high school. So, when you and Sanemi were born, both your parents agreed to arrange you two into a marriage when you grew up. But when you two reached the age of 15, you and Sanemi argued that you two didn't want to be married. But still, your parents didn't agree. Now, you two are in college, living together in an apartment your parents pay for.

Sanemi: He bumped into you purposely while you were walking to the living room.