A/N: Written for the UsaMamo Week 2021 tumblr challenge. The theme for Day 1 was 'Frenemies'. I admit I've never written that theme before so let me know how I did below!

I'd also like to thank romanreloaded for beta reading this for me!

Usagi strolled down the street, lost in utter delight as she munched a pork bun or five. She'd need to fuel up for what was to come.

Mamoru paced forwards, hands in pockets and eyes lowered. He'd need to focus his mind for what was to come.

The pair only just stopped themselves before they collided outside the arcade doors.

"Oh, hello there," they chorused. "... How are you today? Fine thanks, and yourself? Yes, I'm doing great as well. Lovely weather we're having, isn't it?"

Their eyes widened slightly and they exchanged forced, awkward grins.

Mamoru gave a little cough. "My, my oda-... Usagi, those are an awful lot of pork buns."

Her eyes narrowed. "Yes they are... What about it, Mamoru-ba... Mamoru..."

"Just that... um… I feel it is very nice that you decided to bring some for Motoki and your other friends here."

Usagi made a kind of small gagging noise at the back of her throat, before letting out a quick laugh. "Yes. Yes, these are definitely for everyone… Perhaps you... would... like... one… too?" Her voice raised an octave or two towards the end of her sentence.

The corner of Mamoru's mouth twitched, almost like he was going to smirk. Then a resigned expression came over his face. "Thank you very much. That's very generous of you."

He reached out and took one of the pork buns. Usagi's mouth formed into a very thin line. A second later though she tilted her head slightly and grinned at him.

"I have to say I really admire your outfit today."

Mamoru's eyebrow raised a mere fraction. "Oh really, I just threw it on this morning."

Usagi's eyes closed as she grinned wider. "Well, you couldn't tell. And it really makes you stand out as a true individualist."

Mamoru was just about to take another bite out of the pork bun when he paused. "'Individualist'?"

Usagi nodded emphatically, her eyes still closed. "Mmmhmm. Vomit green and thick sunglasses in November?"

Mamoru made a slight gagging noise of his own.

"Few men would have the confidence to go with such a look. I think it's wonderful how you don't care what others think of you. It's so inspiring!"

It was Mamoru's turn to turn his lips into a mere line. "Well... we… we should probably head inside, right?"

Usagi gave a curt nod, and the pair entered the arcade.

"Rei..." Began Luna. "...explain it to us just one more time." Ami nodded in solidarity.

Rei rolled her eyes. "God Luna, you I could maybe understand. But Ami?" she turned her withering glare upon the blunette. "I thought you were supposed to be super smart."

Ami frowned. "Perhaps I'm just having an off-day."

Rei made an exacerbated sound. "Whatever. It's real simple, now that I'm dating Mamoru it means he'll be hanging out with us more. And since he and Usagi don't get along, I asked him to be extra nice to her for me."

Ami's frown deepened. "...And you also...?"

"And I also promised Usagi I'd let her have some of my old manga volumes if she was on her best behaviour with Mamoru."

"...For a whole week?" Added Luna.

Rei nodded. "That's right. For a whole week. I figure that's how long it'll take for the two of them to stop bickering all the time."

Ami and Luna exchanged concerned glances with one another.

"And... And how's it been going so far?" Ami timidly asked.

"That's what we're here to check on," replied Rei as they neared the arcade. "I spoke to them about this arrangement last night, so I thought it was best to get them started immediately."

"Y-y-you actually arranged for them to meet?" Stuttered Luna.

"Yeah, of course. There'd be no point to this week otherwise. I didn't tell them of course, just like I didn't tell them anything else about my plan. That way when Usagi sees Mamoru acting all kind she'll think he's being sincere and vice versa."

"Oh, that's..." Ami's eyes glazed over for a moment as she searched for the right way to phrase herself. "Very... thoughtful Rei."

Luna pursed her lips, as if willing herself to silence.

"Thanks, Ami. I know you're the brains around here..." The three of them entered the arcade. "...but I'm not half bad at planning mys-"

"Did you honestly think that colour was cool? Or are you so stuck up you got dressed with the sunglasses on!"

"At least I'll fit into my clothes tomorrow. You've eaten enough pork buns for a whole army!"

"MAMORU-BAKA!"

"ODANGO-ATAMA!"

Luna and Ami tentatively looked at Rei.

Mouth agape, eye twitching, the shrine maiden remained speechless for several moments. Eventually, she collected herself and inhaled slowly through her nostrils. "Lets'... let's just go..."

The trio departed, leaving Usagi and Mamoru inside the arcade.

A while later (once they were well out of earshot) Rei let out a sigh from the very depths of her soul.

"Sorry Rei," Ami softly consoled. "But you know... there are some psychologists who think that arguing like that can be a sign that two people actually like one another."

Rei looked up mournfully at Ami. "For real?"

Ami nodded. "Yes. Well... on some level... deep down."

Rei sighed again. "For those two it'd have to be subterranean," she moaned.

"Rei, you're just going to have to face facts," chimed Luna. "Usagi and Mamoru are never going to get along..."