@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'