The cocktail party is under way. The clinking of glasses and the guests' voices fill the air, and my sense of hearing is assailed by all kinds of noises.
Suddenly, the voice of someone calling to me reaches my ears.

??? Commander!

Commander This voice...

UMP9 Hehe, we meet again, Commander.

Standing before me, UMP9 seems somewhat different from my usual impression of her.
She's still got her playful and energetic smile, but she's not wearing her usual low-key dark gray jacket. Instead, she's in an evening dress that is elegantly tailored yet still manages to retain an air of youthful innocence.
In my eyes, nothing could suit her better.

Commander Ah, UMP9. Did you finally remember to come say hi after so long?

UMP9 Not quite... I was instructed to participate in a mission today, so I decided to see how you're doing while I'm here.
It looks like you've recovered quite well, Commander.

Commander I've still got a few small issues here and there, but at least I don't need to be confined to an infirmary bed anymore.
As for you...where's the other one?

UMP9 Hehe, you knew I wasn't alone, Commander?

Commander I'm just asking as my impression is that you two are always together.

UMP9 I can't keep anything from you, can I?
Big sis is still making some final preparations, which means there's nothing for me to do, so I slipped out to wander around.

Commander You are sure spontaneous.
Since all the necessary preparations have been made already, and you're saddled with overtime again on a day when we should've been celebrating our anniversary...
...Why don't you take this opportunity as a treat for yourself?

UMP9 covers her smile as she hears my suggestion.
Now that she has received a reason to dig in, UMP9 assaults the tables of food and champagne like a tiger among goats, taking care to drag me along so she could share her appreciation for the food with me.

UMP9 Ahh, this is tasty! This too!
Excuse me, another glass of champagne, please!

Commander Someone's really helping herself.

UMP9 I'm only faithfully carrying out the instructions you gave me, Commander.

Commander You should still keep yourself in check. Don't ruin your pretty dress today.

UMP9 Hehehe...does it suit me?
I've never been to a place like this before where there's delicious food and drinks as far as the eye can see, so I kind of got carried away.

Commander Never? Didn't you attend last year's anniversary celebration?

UMP9 Nope. I missed it because I was on a mission.

Commander That's certainly...

Beep.

UMP9 Ah, hang on, hang on.

UMP9 Hello? Big sis, you're ready? Gotcha, I'll head over right now.
We're about to begin, so I'll be heading off now.

Commander Right, it's just about time for the operation to start.
...Indulge yourself at next year's party to make up for the missed celebration.

UMP9 Heehee, I was waiting for you to say that, Commander...

Some time later...
The ear-piercing alarm makes an enormous racket.
I glance down the chaotic venue hallway and realize that I just brushed by UMP9.
I turn around and call out to her.

Commander Wait, UMP9!

UMP9 What a coincidence, Commander!

Commander Perfect timing. I have some things to ask you.

UMP9 Alright, I'll gladly tell you anything I know.

Commander The jewel seems to have really vanished and nobody knows where it's gone.
Was it you, 9?

UMP9 And why do you think it was me, Commander?

Commander Because you're capable of it.

UMP9 Wow...you really think so highly of me, Commander?
Unfortunately, I don't have it.
But regardless of its whereabouts, the jewel will ultimately be taken to a safe place.

Commander A safe place...
...Huh, I see now.

After mulling over UMP9's words and the events of the party from earlier, a clear picture of the situation steadily develops in my mind.

UMP9 I'll be leaving now if there's nothing else you'd like to ask.

Commander I have one more question for you.

UMP9 Eh? Er...go ahead?

Commander Did you have fun today?

UMP9 How should I say this...
I ate a lot of delicious food, I saw a lot interesting things, and I met a lot of fun people.
Today was an unforgettable day, and I'd like a fun day like today to never end.

Commander Haha, I hope our next banquet will make up for any regrets you might still have today.

UMP9 Thank you, Commander.

UMP9 turns around and quickly runs out of sight.

Several hours later.

UMP45 The mission is over, and the jewel has been returned to the client.

UMP9 As expected of you, big sis. You can handle anything with immaculate finesse.
It's a shame we couldn't keep that big jewel for ourselves.

UMP45 Just following the plan was already much more troublesome than expected, to say nothing of taking it for ourselves. Clearing the records of all those electronic devices was a huge undertaking.
When you think about how complex the job was, the pay does seem quite meager in comparison. What do you think, 9?

UMP9 Me? What do I think?

UMP9 pauses for a bit then smiles.

UMP9 I think...it wasn't too bad.

UMP45 ...What do you mean?

UMP9 Well, the party was more fun than I expected. There were food and drinks and lots of interesting things. Not to mention...
I even got a pretty new dress for free, and the Commander praised me and said I look good in them.
What about you, sis?

UMP45 I'm content as long as you're happy.

UMP9 Isn't happiness the most precious thing?

UMP45 But it doesn't last.

A big, beaming smile spreads across UMP9's face.

UMP9 That's why...
That's why it's so precious, right?