@core578
The sake is most likely a parody of a real product, Shimeharitsuru, which uses the Yamada-nishiki (山田錦) sake rice mentioned last chapter.
The symbol is not メ/me, but rather 〆/shime
@core578
The new girl's is inconsistently spelled throughout this chapter.
コシェ= Koshe/Koche (alternatively 'Cochet')
page4: 'It's Koshe' / コシェだよ, the 'da' is not part of her name.
page5: misspelled as 'Kotetsu'; the preceding 'こっ' might be a stutter (i.e. Ko-Koshe-san') or a shortening of 'kochira'/'this is...', but I'm not sure about this part.
page7: 'Koshe', not 'Kosheda'