To hell with being called 'Master of Kouan', she should be called the 'Goddess of Kouan'! Kouka's appearance is like the combination of movie 2 Kagura & Tsukuyo, which means... she's the sexiest character Sorachi's ever drawn!
Umibozou is greatness. That's an age-old fact, but he's even moreso after this chapter.
One of the most beautiful Gintama chapter's/5.