At the risk of sounding like a killjoy, I have to confess that drinks festivals rarely excite me. These events are often promoted as learning opportunities that can help you improve your tasting skills and discover new brands. While the lure of convenience (the chance to sample hundreds of varieties of sake or wine in one place) has a certain appeal, circumstances tend to shift the focus away from tasting and toward drinking. Outdoor tippling fairs are particularly dangerous and require extra caution. Behind the promise of convivial bonhomie looms the specter of public drunkenness and long, panic-inducing lines for the women's restroom.

So it was with mild trepidation that I joined my friends at the Shibuya Sake Festival at Miyashita Park in mid-May. The fair is produced by Liquor Innovations, the company behind Ikebukero's all-you-can-drink watering hole Kurand Sake Market, which opened in March. The bar features an extensive list of premium brews from producers like Aramasa Shuzo (the makers of Kyokai No. 6, from Akita Prefecture) and Shimizu Seizaburo Shoten (which brews Zaku in Mie Prefecture). But what distinguishes Kurand Sake Market from other specialty shops is its astounding business model: A mere ¥3,000 will get you unlimited sake refills. The Shibuya Sake Festival is run according to a similar ethos. Tickets, which cost ¥3,000 in advance and ¥3,500 at the entrance, come with wristbands that allow multiple re-entry from 11 a.m. to 5 p.m.

The festival, which started last year, took place in Miyashita Park — a narrow trapezoid of urban recreation space equipped with a futsal court — overlooking Meiji-dori between Shibuya and Harajuku. Food stalls selling grilled squid, bentō (boxed lunches), and yaki-udon (fried noodles) stood near the entrance. Groups of revelers picnicked on blue tarps as a band played reggae-inflected Japanese pop in front of a rock-climbing wall. By the time I arrived, it was late in the afternoon, but the party was still going and there was plenty of sake to be had. Pours were both forthcoming and exceedingly generous.