Yatai no onēsan: Tabegoro na monojiri (2009)

The close-knit brothers Kinkichi and Senkichi run a small street-side izakaya. Both are naturally lecherous. However, they have no luck with women, and their daily routine is to peek into a room in a nearby apartment building. But even that leaves them unsatisfied. The woman in the room starts to undress like a stripper, but the curtain is always closed halfway through. Just then, their childhood friend Todoroki walks by. It turns out that Natsumi, the woman the brothers have been peeking into, is Todoroki's girlfriend...