Honestly I'm not 100% sure on the dash rule, tapi from what I hear from my mum friends, JPN boleh accept hyphenated names, a few of us ada kawan yang register nama dengan dash, macam "Nur-Ain" gitu. Best bet is call JPN direct or go to your nearest office to confirm, sebab rules ni boleh berbeza dari satu negeri ke negeri lain, dan they'll give you the clearest answer!