Board Thread:Questions and Answers/@comment-139.195.161.4-20150918125929/@comment-26093926-20150918132550

My condolences to the sword you lost but I don't think DMM provides a way to see your login history :\ Still, it's very unlikely that your account was hacked; there really isn't a point for anyone to try. You could try resetting your password if you're worried about the security of your account.

There were a few cases of swords going missing very long time ago (my own gokotai went missing). The most likely thing that happened is either accidentally using them as refining material or dismantling. Best way to avoid that is to pressing the 'lock' button on the sword you don't want to lose when arranging your team so they don't show up as refinery material or in dismantling (doesn't prevent breaking in battle).