According to NHK (TV company) rules, footage up until 1981 was re-used apart from for special programmes at the time, so they have no footage of this anymore. (Clearly they didn't think ABBA was special enough!). Amazingly, somehow, this footage turned up in early 2007.

ABBA performed Summer Night City and Dancing Queen (both to playback) with a little interview in between (by Takashi Suetune). Summer Night City was cut short before the interview and Dancing Queen was the beginning only before being cut off (however there is no YouTube footage of this).

NOTE: The TV programme レッツゴーヤング (Let's Go Young) showed a full version of Summer Night City (which was a completely different performance from this one, although the costumes, set and camera angles [you would need to see them side-by-side to spot the subtle differences]), and a full performance of the exact same Dancing Queen as this one (although cut short for this programme).

NOTE: VIDEO tab - second video is from レッツゴーヤング (Let's Go Young), included here for the performance of Dancing Queen.

Interviewer: Thank you very much, welcome again to NHK!

Agnetha Fältskog: Thank you

I: Let me ask you a couple of questions, not tough questions at all! You've come out of that screen ...

Björn Ulvaeus: yeah ...

A: ...yes! ...

I: Why is - that's your initials, that's your initials isn't it?

AF: Yes it is, our first names

I: Why isn't it the other way around?

A: We won't tell you, it's a secret!

I: It's a secret, I see. We'll anyway, you have visited so many countries, so many places, how many?

BU: I think we've been everywhere outside South America and China, we haven't been to China yet, we haven't been to Russia yet, but apart from that, almost everywhere

I: Oh, you haven't been to China and Russia

BU: No

I: Do you feel, have you been to Eastern European countries then?

AF: Yes we have, most of them

I: Did you feel anything different when you are there?

Benny Andersson: I think the audience is much more receptive because they're not used to, to have visitors that plays rock 'n' roll and pop music from the western world.

I: This is rather a tough question, may I ask you this question? It's about your income. I hear that your annual income is much larger than that of Volvo, is that true?

BU: (laughing) That's not true, no!

AF: you'll have to ask Volvo about that!

I: I see

Frida Lyngstad: And we are paying a lot more tax, you know

BA: A lot more than Volvo, I think

FL: yeah, I think so

I: How are you spending the money you gain?

AF: You know we try to invest them in different things, houses and so on, we have to do that

I: The houses? For your own property?

BU: Ah well buildings, you know,

AF: yeah

BU: ... in the city of Stockholm

I: Here in Japan, we have a pair of young ladies, singers, they are called Pink Ladies

BA: Yes, we heard about them

I: Their performance and singing are very much like yours

FL: We haven't seen them so we don't know

AF: Maybe we'll get a chance to see them when we are here

I: Well, so much for the interview ...

BA: Thank you very much

I: ... what was the next performance?

AF: We'd like to do Dancing Queen

Lyrics available on the Official ABBA site: Summer Night City and Dancing Queen

Thanks to Marcus Bergs, Mark Walton, Jun Seo, Sam Shervz, Jozsef, Michael Price (and his Japanese ABBA book!).  Huge thanks to Mayumi Taheri for identifying the programme and extra information.
YouTube links c/o The Piper Chile