Kosuke’s “dirt” is caused by the horny dream that the devil Kuroto shows. Fauna is enthusiastic about purifying the “dirt”, but Jord cleans it first …!
Kosuke invites Fauna, who is depressed, to the pool in the amusement park to change her mood. The power of Kuroto is added to it, and it develops into a stronger “dirt” !! It is said that Astra flowers are needed to purify this “dirt”.