Summary:

Mikio and Yukio are twins. Or that's what was said until Mikio heard that they weren't blood relatives, and his own sister also liked him! Obviously it was a great shock to him! And a strange and unbelievable thing happened where they switched bodies due to an accident! What's even weirder is...... "I think it's time to stop playing around. Miki-nii, you must always be mine alone." Her pure and innocent little sister now has turned 180 degrees and becoming a possessive person to him! How will Mikio now have to deal with this problem and his new life?