My Senior Sister Is so Tough

What is it like to have a senior sister who is younger than you? "Chi Zhou! If you cause trouble for me again, I will hang you on the top of Wanyue Tower." "Senior sister, don't do this! I'm going to avenge you again. Look at that kid who's been looking at you." "If you keep doing this, I really won't have anyone to marry." "Hey, senior sister, don't you still have me here?" That night, a handsome young man appeared upstairs in Wanyue...