S4·E27 It's Bad Luck to See a Spider at Night

Gintoki and the gang return to Yoshiwara at Hinowa’s request for the first time in a while. Although Hosen’s death has brought freedom to Yoshiwara, it’s also drawn the renewed interest of those who previously avoided Yoshiwara in fear of Hosen’s power. Yoshiwara is now troubled with an increased crime rate, especially illegal drug dealing. Odd Jobs are asked to capture the man responsible. The man in question is said to go by various names, titles, and even faces. The only clue available is the tattooed spider on his neck.