A Couple Of Cuckoos Vol. 3 (Light Novel)

In Vol. 3, just when Nagi and Erika are getting used to their new life living together, Nagi’s sister Sachi suddenly moves in! Nagi just wants her to go back home, but she just wants to spend more time with him! Later, the love quadrangle intensifies when Nagi goes on a date with his crush Hiro to an amusement park!
Notice: This book is written in Japanese.