You got picked for getting a remodel!Listen to me, Hamakaze!It's great that you've gotten B Kai, right!Listen to me!Ushio.Have some time off and take her to an onsen or something, would you?I know all about it! Right from the start!Breasts...You're wrong! It's B Kai!I heard you! It's B Kai, isn't it!Just B!
乙改 can be read as /okkai/ (otsu+kai), while 'breasts' can be /oppai/; dialogue changed to maintain joke.Okay.Anyway, that's my chair!
Move!That's just short for Breasts Kai, isn't it!
Hamakaze says /paiotsukaide-/, which is a feminine slang reversal of /oppai dekkai/ - 'huge breasts'