NTT Flets Hikari always goes with a router and provider?

I was always under the impression that if you go directly to NTT to inquire and have a contract, that they can just help you with construction, provide you an ONU without router, an that’s it. I currently have Biglobe contract through au and it has a router with it. But I wanted to use my own router/firewall homelab setup without the need or paying for additional rental router cost. Anyone know if that is possible?

I am moving to a new house and was wondering starting fresh with NTT cos I had installed my Biglobe through au back when I was still bad in Japanese communication, but if they are also sending me to another “provider”, then better off just cancel my application for NTT Flets. Any inputs are welcome. TYIA!

by genkiganko