I tried translating Arashi's talk from the Music Station 2 hour special on 2017.10.13, before they performed Song For You and 未完.
Anything written in [square brackets] means I added it, probably to add extra information. Anything underlined means I'm not sure if I translated it correctly. There were a few really long run-on sentences (the culprits are Jun and Sho) which I broke up for easier reading.
Please let me know if I've made any mistakes!
Updated translation on 2018.06.25 thanks to ilifebook's helpful comment, and added a translation of Arashi in Mini Station.
Japanese transcript: arashi-transcripts
Raw from arashigoodies, yumenohashi (DW)
Mini Station (with the host Hironaka Ayaka, and guests including Arashi and Takahashi Katsumi)
Hironaka: Tonight's Music Station is a 2 hour special with Arashi [and other guests].
[Other guests talk]
Hironaka: And Katsumi, you've met Arashi before, haven't you?
Katsumi: Yes, last year I also went to Osaka Dome. [TN: Presumably to Arashi's concert]
Katsumi: Huh? Why aren't you saying anything? I did go, didn't I?
Nino: Um, this is the first time we've met him.
Hironaka: Is that so?
Katsumi: With Ninomiya, it was about 15 years ago, that, um…
Hironaka: You acted together, right?
Nino: Sorry Katsumi, they're running out of time.
Hironaka: Well, let's take a look at tonight's highlights! Sorry!
[VTR summary: I haven't actually seen the full VTR, as I've only been able to find short clips of it. I think it ranked groups by their annual CD sales, and Arashi was in these rankings. There was also a clip of one of their performances of "One Love" and their Arashi Around Asia concert in 2008. I think Sakurai is referring to this when he says "related party".]
VTR: Arashi has sold over 33 430 000 CDs.
Tamori: Arashi, you said "woah" during the VTR, so you didn't even know how much you had sold?
(Simultaneously) Aiba: Not at all. Matsumoto: I had no idea. Sakurai: I was surprised.
Nino: I was astonished.
Sakurai: I was having fun watching the first half of the VTR, but in the middle we became a related party to the VTR, so I felt tense, but I was surprised.
Aiba: Thank you everyone who bought our CDs.
Sakurai: Thank you very much.
Nino: Thank you.
Hironaka Ayaka (female host): That's really great.
Tamori: Amazing. You surpassed 30 million sales.
Sakurai: I can't really imagine it.
Matsumoto: When watching the VTR, groups like Mr. Children left a great impression, you hum their songs to yourself. It's unbelievable [how much they have sold].
Tamori: That's amazing, isn't it.
Hironaka Ayaka: Yes. Well, tonight, Arashi will perform for the first time a special version of their new song, only on Music Station.
Tamori: What kind of song is it?
Aiba: 「未完」 is the kind of song that blends music from various genres, and it's a song which isn't consistent.
(Simultaneously) Sakurai: Wait- Matsumoto: No, hang on, you mean that in a good way, right? A good way.
[I love Aiba's face here]
Aiba: A good way, a good way. In a good way, the song isn't ordered nicely. It isn't just smooth the whole time. It's a good thing, a really good thing. [TN: I think Aiba means the genres jump around in the song so it's not a neat song]
Matsumoto: This time, the name of our album is 「untitled」. We tried making the album include components of Arashi up till now, as well as experimental efforts. It expresses things we haven't done until now, and focusses on Arashi from now on. We made it with that kind of concept in mind.
Tamori: Today there's a video clip which you've already pre-recorded?
Sakurai: Yes, this time, we're doing a performance which we haven't done up till now, so it was the first time, on a day which wasn't today's live broadcast on a Friday - actually it was last week - that we went to Terebi Asahi's studio and filmed the video clip. "Doctor X" was being filmed next door.
Matsumoto: "Doctor X".
Tamori: They were doing "Doctor X"?
Matsumoto: Daimon-san was there.
Aiba: We were able to see it raw. I'm glad.
Sakurai: "I'm glad"? It was fresh. We did the pre-recording, and the clip has been edited a little, so it flows.
Tamori: Sakurai-kun, there's rap in this song, isn't there?
Sakurai: I'm much obliged.
Tamori: What do you mean, you're obliged?
Sakurai: Well, um, amongst our album's songs, there's always some songs I've been allowed to write. But I was wondering if recently there's been rap on Music Station? It might be that there hasn't been any rap recently.
Tamori: There weren't any?
Hironaka Ayaka: It might have been a while.
Matsumoto, to Sakurai: Are you alright?
Matsumoto: At rehearsal he was saying he wasn't able to sing at all.
Sakurai: The rap I wrote myself won't come out. Even though I was practising a lot earlier. I'm still nervous now.
Tamori: Although you're going to sing for us just after this, how are you feeling?
Ohno: This time, there's a move in the choreography where I roll across MatsuJun's back. Whether or not I can do that move, though…
Sakurai: You can do it! That kind of highlight.
Tamori: Is it difficult?
Ohno: I wonder if I can do it properly.
Nino: You can do it.
Sakurai: All eyes will be on you.
Tamori: The whole thing will be unordered? [Tamori is referring to Aiba's earlier comment]
Aiba: Yep, it'll be scattered.
Nino: It's a good thing!
[Look at Ohno's face XD]