The "third beer" market emerged without me knowing anything about it. This article brought enlightenment.
Asahi Shimbun: Third-beer market on verge of price war
Just as the dust looked to be settling on the low-malt beer price war, a new battle appears to be brewing in an even lower-price segment-that of so-called third beer.
...The fear now is that the price war will spill over into the new segment, whose third beer retails for about 100 yen per 350-milliliter can, including tax. By comparison, happoshu sells for between 115 yen and 125 yen.
Sapporo Breweries Ltd.'s Draft One, a third-beer made from peas, went on sale nationwide in February.
...The two industry giants, Asahi Breweries Ltd. and Kirin Brewery Co., have yet to enter the third-beer market.
"If one or both of these companies were to wade into the battle, the overall market of alcoholic beverages would resemble a full-scale nuclear war,'' one industry source said. "At present, the market is in a Cold War state of uncanny parity.''