Narita Airport Lounge

Hi I will be traveling NRTSIN on Business Class, what lounge is available? I can’t seems to find it in SQ website.

Aside from that, during initial booking, HND is fully booked, now that I saw there’s one seat open, I’m not too sure I want to change if Narita airport is better, plus I’ve flown in HND so I’ve seen it. Plus HNDSIN last seat is near toilet, I’m trying to avoid that.

Any advise will be greatly appreciated 🙏🏻