Summon Night Craft Sword Monogatari

Complete the game and save. Now reset and you can start a new game but with your previous money, bestiary, weapon levels, special attacks, etc...

After you complete the game go to the top right corner of the fishing area to find a person there. You can choose 6 of your current weapons to be given to him, and these weapons will be the ones transferred to you when you start a New Game+.