Apologies for bumping an old thread, but I am hoping to avoid a misstep on my first domestic flight in Japan. Family is planning to grab an HND-ITM flight after arriving from the US. We will be carrying an underseat bag and a duffle-style backpack. We will not be over the size restrictions, but it's likely that the combo of bags will be over 10 kg. Should we just check the duffles once we get to T1 or just try to carry them on? Travelling on AA award redeption with OW Emerald status, if it makes any difference.