This chapter is basically a filler chapter. Due to a lot of slang, it was very hard to translate, so forgive me for not going into detail about it . So here is goes:
Three of the dimmerwitted yakuza find a pair of underwear in the hall. They assume it’s Sachie’s underwear and conspire to get out the situation. Unfortunately, they choose to hold on to the underwear and not tell anyone about them. While kicking back at a Yakari’s lounge (or maybe a brothel), they fumble around and alcohol gets spilled on the undies. Meanwhile, Sachie notices a pair of her undies are missing, which sets everybody in search of a panty thief. The yakuza try to replace the underwear, but instead scare the shopkeeper at the lingerie store. Sachie and crew happen up on the guilty yakuza as they are being thrown out the store and they finally ‘fess-up. The underwear they picked up, though, is not Sachie’s — they are “grown-up” panties as opposed to “high school” panties. And so everybody’s off, again, to find the underwear thief. Back at home, Yukari is there in plain clothes. She says she came to deliver something and that she was present the day the yakuza found the sexy panties, which is the same day Sachie’s panties went missing. Igarashi doesn’t like the story and believes Yukari knows more. While the the rest of the household is trying to lure the panty thief out, Igarashi goes to question Yukari more about what she had to deliver to the boss in so much haste. Yukari says she can’t tell him that, but she can tell him that Sachie’s missing undies are red.
Now onto what really happened — apparently Sachie’s grandfather spotted a pair of Sachie’s panties in the pond in the yard. He freaked out and asked Yukari to buy a replacement pair. Yukari came to deliver the replacement underwear. The dogs show up with the bait underwear in their mouths, implying the dogs are to blame for the missing panties and the panties in the hall. Also, during this time, a real underwear thief is caught falling for the bait.
Sigh … I hate filler … I burned so much time wading through this chapter … The next chapter looks a lot better though. Thumbing through it, it seems that Igarashi gets pissed and sad when he overhears Sachie’s grandfather say that he wishes to find a good guy outside of the yakuza for Sachie to settle with.