Hijacking this to ask if anybody has experience of going to London from Tokyo on ANA?

I'm headed to London mid year, but weighing up going a bit of a weird route (through Japan) as have some family there too I'd like to see and a few sights I didn't check off my list on my last trip. I appreciate it's not a conventional route. Would fly on Air NZ to Tokyo.

If possible I'd prefer to stick to Star Alliance as I'm hopeful this trip will also get me enough SP (combined with other upcoming travel on Air NZ) to retain elite ... only BA, JAL and ANA do direct flights from Tokyo to London and ANA is the only Star Alliance carrier out of those three.

Unlike OP, I'll be travelling economy unless I either come into a bunch of extra money or there's some amazing 'no brainer' deal e.g. premium economy for not much more than regular.

Will probably just fly home on Singapore Airlines, or maybe United via Los Angeles (I just really dislike transiting through USA)