Gyokuon Attack!

Nagi and Jin are surprised by Tsugumi Aoba, a classmate and friend of Jin, paying a visit to him. Nagi sorts things out by fabricating a story about her being Jin's half-sister who started living with him. Later, Nagi and Jin end up having a serious discussion and she flees the house. Nagi returns to the sacred tree's place and finds a kid playing there with an impurity in his body. Nagi tries to cleanse it without Jin's help, just to find herself in danger. Jin appears in the nick of time to save her and he ends up carrying an injured Nagi back home.