glass, cup
盃 centers on a small vessel for drinking: a glass or cup, especially for sake.
盃 combines 不 (not) and 皿 (dish/plate), but the historical origin is uncertain. It may have originally depicted a specific type of cup, with 不 possibly contributing a phonetic element.
The top 不 looks like a lid or a tilted cover, and the bottom 皿 is a dish. Together they form a cup with a cover, like a sake cup.
For ハイ, imagine raising a cup and saying 'Hi!' as a toast: Hi -> ハイ, and the cup is raised high.
pure double chow; winning hand containing two identical chows (i.e. same numbers and same suit)
pure double chow; winning hand containing two identical chows (i.e. same numbers and same suit)
winning hand composed of two sets of two identical chows plus a pair
toasting; drinking to someone's health