She's got crippling anxiety. Her go-to for every conversation has been to shut the other side down and simplify everything to an adversarial/transactional dynamic that she understands. That's not a fun way to be at a party. Her fallback would probably be to hide behind Aki the entire time, but she doesn't think Aki & Iroha's relationship would let that happen either.So she'll just stay at home and cry under the sheets.