Move between left and right sides of the backstage area/homescreen. Can change to a forwards/backwards arrow depending on where you are in the room (?).

Likely a fullscreen/view mode, that removes the UI temporarily.

Unsure. Something to do with altering the UI for the room like the other 3 buttons in this area. Possibly to do with moving the characters or yourself around the screen. Potentially some other kind of customisation, although that seems to be the function of #20.

Likely a toggle for the text box (#14). It is greyed out temporarily, possibly when moving between left and right sides.

User rank and level up bar.

LP (likely still 'live points'). Used up to play songs in the rhythm game, and replenished by waiting in real time.

Likely a shortcut to refill LP with in game resources.

Likely the Live Emotion equivalent to 'Prisms' in Shining Live. Used for the gacha and other in game functions.

Home? Unsure exactly what screen this may return to, since the official tweet refers to this backstage area as the home page.

Settings/options menu.

News/updates log. Unread information indicated by a red diamond top right.

Missions, goals or achievements. Likely that completed missions with unclaimed rewards are indicated by a red diamond top right.

Giftbox. Unclaimed gifts indicated by a red diamond top right.

Chat box transcribing what the speaking idol is saying, as well as their name.

Text reads: "Beginner Mission". (Text in white below this box just says that the game is still under development).

Speaking idol. There can be multiple idols in the backstage area at once (Camus seen in the background). They are represented by 3d models, and it looks like they will interact with the background and eachother. In this case, Otoya is speaking to the player, and Camus is inspecting a book in the background. Almost certain that the outfits and room can be customised.

Button to navigate to viewing 'Emotional Pieces'. Not exactly sure the best way to translate that, despite it being in Katakana, but 'Pieces' (?) seem to be the equivalent to photos/cards in Shining Live. So I'm assuming this will be the way to view, organise, level up etc all your collected pieces, whatever they may be. The icon makes me think of the cards from Aikatsu, with different cards representing different parts of a while outfit. It makes me wonder if there'll be a bit more of a dress-up element, where you can collect and mix and match different headwear, tops, and bottoms of clothing sets. Please let me know if piece/peace means something in this context that I dont know about!

Button to navigate to the 'Piece Gacha'. The system for obtaining 'pieces' via in game currency.

Button to navigate to the story. Like other things on the UI, it seems like unlocked but unread stories are indicated by a red diamond.

Button to navigate to 'MiniPri'. Likely either or both) a view with cute chibi versions of the characters and backstage area, or the way to customise the members and background of the backstage area. I wonder if you can unlock different furniture, wallpapers, floors etc, and move them around yourself, of if the backgrounds are set.

Cecil: You haven’t talked much with Camus, have you, Shion? If you like, I’ll introduce him again. This is Camus. My senpai. He may be stern like a devil at times, but that's because he cares about his fans, so don't worry, there's nothing to be scared of.

Camus: Cecil, please do it more seriously.

Cecil: (startled meow) Err… Occasionally… No, sometimes… I mean, very rarely, he shows his kind side.

Camus: That’s always a mistake you make, isn’t it?

Cecil: … Is that so?

Shion: I am grateful for the introduction. It seems like the two of you deeply trust each other. I sense you have a wonderful relationship.

Cecil: What part of our conversation gave you that impression?

Camus: Anyway, now it’s your turn to introduce yourself.

Shion: I would like to start with HE★VENS. They are the most important thing to Amakusa. Each of them has their own merits.

Camus: What I want is to hear about you. Take your time and tell me.

Shion: Oh, I’m afraid that would end up being too long a story.

Cecil: A rare day has come! Camus is very kind.

Camus: You shut your mouth. Don’t get in the way while he’s talking.

Shion: About me… Oh, that’s right. Amakusa prefers towels that are soft to the touch. I brought some spare ones with me today, so I would like everyone to use them.

Camus: Hm? Really? In that case, I'll offer you some of my favorite sweets later, too.

Cecil: Then, I will prepare the drinks. It's kind of fun, isn't it? It seems like the three of us will get along very well.

Shion: Amakusa feels the same way as Cecil. The atmosphere is different from usual and it feels fresh and comfortable.

Cecil: Ah, that’s right.

Camus: That’s right.