Yukako Yamagishi Falls in Love (6) (山岸由花子は恋をする その⑥ Yamagishi Yukako wa Koi o Suru Sono 6), originally Offense and Defense in the Entrance! (玄関の攻防！ Genkan no Kōbō!) in the WSJ release, is the two hundred ninety-ninth chapter of the JoJo's Bizarre Adventure manga. It is also the thirty-fourth chapter of Diamond Is Unbreakable.
As Yukako furiously heads back to the house, Koichi must resist her until Josuke arrives for fear that she's take him away to another place. He takes the electric chair and nails it to the front door, hoping that it will stop Yukako. Having blocked the door with other pieces of furniture, he successfully prevents her from entering, confident that Yukako won't break the windows as to not attract attention. Yukako, stuck outside, confesses that she is happy that Koichi possesses a Stand too, and interprets it as them being made for each other. However Koichi electrifies the handle, which angers Yukako. Echoes then puts the sound "I hate you !" on Yukako's cheek to drive her away, but it reveals ineffective, Yukako literally not taking these word into account, her obsession being too strong. Koichi then feels that his hair is being pulled backward by Love Deluxe's power and is smashed into cabin. Still stunned, he is then smashed against the electric chair which destroys it and enables Yukako to slightly open the door. She then declares that one way or another Koichi will love her or he'll die. At the brink of despair Koichi tries to use Echoes, but the Stand has petrified itself and remains still. Echoes begins to lose its color and Koichi thinks that his Stand died out. However the cocoon sheds itself, revealing something inside it.