With its "Delicious (or Oishii) Milk Shake", Sangria claims to have been the first company to sell milk shakes in PET bottles in 1998. This was by using a special aseptic filling method. No other details, but it tastes fairly good and has a fairly long shelf life despite containing milk and eggs. サンガリア おいしいミルクセーキ
Photo is a web capture for explanatory purposes, copyright belongs to the company.