'Violence Jack Off' is - don't laugh - a shop in
Tokyo, selling trendy clothes. It opens from
8am to
10pm, and despite being something of an
urban myth it is actually a real store (a friend of mine has been there). It's just outside the
Futakotamagawaen station on the
Tokyu railway line, apparently.
The name is part of a phenomenon whereby Japanese shops, t-shirts and products aimed at the youth market are emblazoned with random English slogans, in much the same way that Japanese kanji are a popular accessory for hip Western designers. The other canonical example is the t-shirt slogan 'Spread Beaver: Showing The Vaginal Area'.
Engrish (the node) has many more examples of this, as does http://www.engrish.com/, the website.