Thanks for the heads-up.The hachiyas when underripe have tannins. I would describe it as making your mouth implode more than slight bitter taste. They make your tongue numb and kind make you feel like you are on drugs, or dying. But when they are ripe they are fantastic! The fuyus you can eat at any stage of firmness/ripeness.
And for the hachiyas the ripeness I look for is the consistency of pudding, just the skin holding the whole thing together. Way riper than most people think is reasonable.