Younger Brother: After going through life and death and countless hardships, I finally made it out of the infinite space alive. But something went wrong as I was leaving, and I turned into a baby. My older sister found me and took me in. Since you're my sister, I'll use every bit of strength I have to protect you. No one will ever hurt you!
Older Sister: The little brother I found as a child grew up to be a dependable man. I became an idol and found reliable teammates. Two happy things should have made me even happier, so why did everything turn out like this? My teammate became my little brother's girlfriend! And you have the nerve to say you love me, little brother! Are you trying to have a threesome with sisters? And why is even my senior involved?! She's your ex-girlfriend!
