Hanzo would draw his swords, assuming a defensive posture as he'd move in through the front door, expecting to find a fight going on, but he didn't want to be caught off guard and have a bandit do a lucky shot.  He is fairly certain Emi will be following him in armed given that she sees what he sees and he is walking in armed.  He tries to take the lead in through the door, in the hopes that the bandits will fail to strike him and leave themselves open for Emi-san to come in and strike the first blood.