In the Crystal Brighthouse, balloons and streams were on the floor, and Izzy chanted and scatted in excitement."It's T.U.E.S. Day! Woohoo!" she cheered and chanted with joy. "Uni-KA! Uni-KO! Uni-FA! Uni-FO! Uni-MEE! Uni… MOH!" she ended with a holler that caused the Brighthouse to shake.

Sunny, Zipp, and Pipp looked at Izzy strangely while eating breakfast. "Uh... No, Izzy. It's Thursday," she pointed out, not getting what Izzy meant. Then she looked at the time and saw it was about to be nine and gasped. "Aah! And I'm late to open the smoothie court!" she cried out as Zipp and Pipp also saw the time and ran off to their daily routines.

"Ugh! The pegasus marathon already started!" Zipp cried out as she put her things for the marathon in her bag.

"Mane Melody can't open without the mane attraction!" Pipp boasted as she put some makeup on her face.

"No, it's T.U.E.S. Day. T. U. E. S. The Unicorn Expression of Sparkle Day! A special day for every unicorn…" Izzy tried to explain what she was talking about, but the rest were too busy preparing for the day. Sunny got into her roller skates and, alongside Zipp and Pipp, ran out the door since they were late, leaving Izzy alone and sad. " ...and their friends..." she finished with a sigh. She walked over to the table and looked at her reflection in a cereal with a sad face. "I miss Bridlewood. Earth ponies and pegasi are great, but it'd be nice to make another unicorn friend..." she said with sadness. Then, something came to her mind, thinking of somepony, or better say, some hedgehog. "Maybe Sonic is free! I hope he let me explain properly..." she said, trotting upstairs to the bedroom.

Meanwhile, Sonic was holding one Chaos Emerald in each hand, with his electrical powers activated, trying to make the Emeralds glow and shine again. But as it had been since the Emeralds created the map two months ago, they were not shining anymore, not even with his new powers.

"Did something change?" Hitch asked on the other side of Sonic's cellphone since they were talking on a normal call 'cause Hitch needed to attend his work in a few minutes.

"No..." Sonic answered with disappointment. "This is starting to worry me, Hitch. There's no sign of the Emeralds activating again. I've tried everything I know, even shouting 'Chaos Control,' but nothing happens! And I've already looked under every unknown place of Equestria, and yet haven't found the other Emeralds..." he explained with worry, as he got close to a copy of the map he had - since Hitch had the original one - and marked an 'X' on another location.

Hitch did the same in the station, in the same spots on the map Sonic told him to. "And we haven't discovered anything about this Opaline nor the Castle they live on..." Hitch stated, looking worried at the board with all the information he and Sonic had gathered over the past five months. We're approaching the dead end, aren't we?" Hitch asked, concerned.

"I'm afraid so..." Sonic answered back on the Brighthouse. "I think we should leave it for today, Hitch. You have to work, and I need to clear my mind..." he stated while rubbing his eyes with one hand.

"Ok then. See you later, Sonic," Hitch said.

"See ya..." Sonic said back and finished the call. He put his phone back on his quills, then put the Emeralds on the bag and hid it under the mattress. Once he put the mattress in place, he sighed and leaned on the bed, looking at the ceiling and wondering why the Emeralds weren't working anymore.

A moment later, Izzy came into the bedroom smiling and found Sonic lying on his bed. Sonic heard the door opening and sat down, wondering why Izzy was so excited.

"Morning, Izzy. What brought you up here?" Sonic asked with a smile.

"Hey, Sonic! Do you, uh, wanna celebrate T.U.E.S. Day with me?" While Sonic looked at her in confusion, Izzy asked, stood up, and walked towards her.

"I thought today was Thursday..." Sonic said, scratching his head, not understanding what she meant.

"Not Tuesday, silly. T.U.E.S. Day," Izzy corrected. "It is short for ‘The Unicorn Expression of Sparkle Day’! It's a special day for every unicorn to celebrate friendship with their friends!" she added with a squeal, then made the motto she did earlier. "Uni-KA! Un-KO! Un-FA! Un-FO! Un-MEE! Un… MOH!!!" she said the last part with a holler that shook the room as she finished with a smile.

"So that was what made the room shake before..." Sonic said while he scratched an ear. "Never heard about that, but I gotta say that a free day with your friends sounds like fun. Do the rest know about this?" he asked with curiosity.

"No..." Izzy said in a sad tone. "I tried to tell them what the holiday meant, but they thought I was talking about the day of the week. And when I tried to explain it, they just ran off in a hurry since they have plans today; they didn’t even stop to listen to me when they were in a hurry!" she said with sadness and sat down. "And I know Hitch will be busy with his job as a sheriff, so he’s out of the question..." she finished.

Sonic looked at her and felt bad but also a bit mad that his friends didn't even take a moment to listen to Izzy. "Man, that sucks. I get they were late, but listening for a moment wasn't going to kill them," Sonic said aloud with a little anger, then looked back at Izzy and smiled. "Lucky for you, I'm free today, and I'm not starting to work until next week," he pointed out his schedule. "Besides, you say it yourself: it's a special day for unicorns and their friends, and I'm your friend, after all," he stated with a smile.

Izzy's eyes sparkled, and she started to jump in excitement. "Really?! Thank you so much, Sonic!" she called out, hugging Sonic very tight.

"Anything for my friends!" he replied, trying to catch his breath. "Now, could you let me go so we can enjoy the day?" he asked, wanting to feel his breath again.

"Oh, right, sorry!" she said in embarrassment as she let Sonic go, who sighed in relief and caught his breath.

"Great... Let's go out and have some fun!" he yelled excitedly as he and Izzy ran off to the main door and shut it.

At Mane Melody, Izzy was getting pedihoofs and giggled at her hooves' rainbow colors. Meanwhile, Rocky was giving Sonic a little massage on his back.

"This is goooooood," Sonic said with satisfaction as Rocky massaged his back.

While Izzy giggled at her pedihoof, Pipp watched from a distance at the two having fun and frowned, thinking this looked like a date.

Later, Sonic and Izzy were in the movie theaters, with Posey behind them, watching the ponyfied version of Transformers, 'Trottformers.'

Sonic and Izzy saw the leader of the Trottformers, the ponyfied Optimus Prime named 'Optimare Prime,' giving orders. "Trottformers... Roll out!" he called out to his offscreen comrades.

"Wow!" Izzy cheered as she giggled at the movie.

"Man, this movie is already better than the Michael Bay movies back home, and that's saying a lot!" Sonic joked as he ate some popcorn.

"Autobots... Transform!" Optimare Prime announced in the movie, and Posey fell to the ground with a groan as she hit the floor with a thud. Sonic and Izzy turned to see what the sound was but found nothing and resumed watching the movie.

Izzy drank some grape soda and tossed the empty can away, hitting Posey in the head.

"Ugh..." Posey groans from being hit with a can.

A while later, Izzy and Sonic were at a spaghetti restaurant. Izzy ate some from her muzzle, but when she got her head up, a whole tomato on the spaghetti got caught on her horn, which she didn’t notice.

Sonic laughed at Izzy's horn with the tomato. "What?" Izzy asked in confusion.

"Ahahah! Look at your horn, Izz!" Sonic said while laughing.

Izzy looked at her horn and realized why Sonic was laughing in the first place. She then snorted and laughed with Sonic because she also found it hilarious.

Hitch, who was doing his rounds around the town, noticed the unicorn and the hedgehog having so much fun and then smiled.

"Hmm… I wonder what got those two happier than usual... " Hitch wondered since he knew they were both usually hyperactive and optimistic, but today they were happier.

Later, Sunny was blending her fruits to make smoothies when Sonic and Izzy came to the booth.

"Two strawberry sunshine, please!" Izzy requested.

"Coming right up!" Sunny said as she blended the smoothies. When she turned to the front of the boot, she saw Izzy and Sonic in front of her. "Oh, hey, guys. Nice to see you!" she said with a smile, then noticed Izzy's pedihoof and that Sonic was wearing one of Izzy's friendship bracelets because Izzy gave it to the hedgehog as a thank you for passing the day with her. "Wow, seems like you guys are having fun," she commented.

"You bet!" Sonic said with a smile. "A day at Mane Melody, a movie, lunch, and smoothies. We're having tons of fun today!" he assured.

"Well, it's good to see you two having fun," Sunny assured with a smile. "Although you are way too happy today..." she finished while raising an eyebrow and giving them the smoothies.

"Thanks, Sunny!" Izzy thanked Sonic as she and Sonic grabbed their smoothies. Sonic gave Sunny some bits to pay for the smoothies.

"Happy T.U.E.S. Day!" both Izzy and Sonic said as they walked away with a smile.

Sunny giggles at Izzy. "Sonic, I think Izzy got you confused. It's Thursday today, not Tue--" she was saying, but that's when she realized what Izzy really meant. "OH! T.U.E.S. Day!" she cried out as she went through the stuff she kept in her bag, looking for the journal as she completely forgot about the holiday.

"Say, Sonic. Wanna race back to the Brighthouse?" Izzy asked with a smirk, her smoothie floating with magic.

"Oh, it's on!" Sonic said as he smirked back.

Sonic and Izzy started to run away playfully as they passed by Hitch and Zipp. "Anypony think Izzy and Sonic are even more energetic than usual today?" Hitch asked in confusion.

"Yeah. I was flying, and I thought I saw them hang out all day having fun," Zipp commented as she chuckled. "I mean, I know those two are very energetic, but today is different..." she added.

"Well, if you think about it, Sonic was Izzy's first friend. And... Izzy is also the first friend that Sonic made when he arrived..." Hitch realized. "Perhaps they're just bonding their relationship a little bit more," he theorized.

"Yeah, yeah. How cute..." Pipp said, a little mad, as she came next to Hitch and Zipp with a frown. "They arrived at Mane Melody earlier, and they were having a good time..." she explained with a little disappointment, which caused Hitch and Zipp to look at each other, worried that Pipp may have misinterpreted things.

Sunny found her book, brought it down on the counter, and opened it. She looked through it and then found what she was looking for. "See? Today isn't Tuesday," she told her friends in front of her with a smile.

The three looked at her with smiles. "Yes, Sunny. We know," Pipp said with a smile.

Zipp smirked. "I think she's forgetting the week, too," she said to Pipp as she turned to Sunny with her hoof raised. "How many hooves am I holding up?" she asked with a smile.

"No, today isn't Tuesday. It's T.U.E.S. Day—The Unicorn Expression of Sparkle Day!" Sunny explained as her friends looked on in shock. "I can't believe I forgot! It's a special day for unicorns to celebrate friendship," she told them with a smile.

That's when they realized what Izzy meant in the morning. "Oh! That’s why those two were having fun all day together. Izzy must’ve told Sonic about T.U.E.S. Day!" Hitch said.

"Wait... so they were just celebrating?" Pipp asked in disbelief, now feeling guilty of misunderstanding the situation.

"Guys, we have to make it up to her... to both of them," Sunny said confidently as the other nodded.

Later that evening, Izzy and Sonic walked back to the Crystal Brighthouse as Izzy grunted and sat in front of the Brighthouse door.

Sonic came and sat down in front of her. "I told you all that pasta was going to hurt later," Sonic said with a little smile.

"Sorry, Sonic. I should not have had all that pasta..." Izzy apologized as she rubbed her belly to ease the ache a bit. "We had a fun day, Sonic," she told him.

"We sure did," Sonic replied with a smile, but then he frowned when he remembered that the rest of their friends didn’t join them. "But it would've been even better with the rest," he said with a sad look.

"Yeah..." Izzy said in agreement as she frowned a bit. "It just doesn't feel like T.U.E.S. Day without my frie--OUAUGH!" Izzy cried out as the door suddenly opened, and she fell on her back.

Sonic saw this and immediately ran towards her. "Is everything okay, Izz?" he asked her.

"I’m fine, but who opened the door?" Izzy asked as she and Sonic saw their friends circle them with smiles.

"Happy T.U.E.S. Day! Uni-KA! Uni-KO! Uni-FA! Uni-FO! Uni-GO!" Sunny, Hitch, Zipp, and Pipp cheered in unison as they repeated Izzy's chant from the morning.

As they now remember, Izzy smiled at her friends, but Sonic was still a bit mad. "Aw, you ponies remembered? Uh, did you just pretend to forget?" she asked them with a smile, thinking that her friends were just playing tricks on her.

"Yeah, did you just casually remember the holiday now?" Sonic asked with an accusing look.

Sunny and the others looked at each other with guilt on their faces as Sunny spoke out. "Well... No. We forgot," Sunny confessed to Izzy and Sonic, then got in front of them while Izzy got back up. "We are all still learning about everypony's special days, and I guess we need to try a bit harder," she finished with an embarrassed smile.

"We're sorry, guys," Pipp apologized with a smile.

"Sorry," Zipp added with a smile.

"We'll do better, I promise," Hitch finished as the four friends smiled.

"But we were thinking... Maybe there's still time to do our own T.U.E.S. Day! All together?" Sunny asked as she and her friends wanted to make up for Izzy and Sonic.

"Are you kidding?! Sonic and I had a whole day of fun, and now we have to do it all again with you ponies?!" Izzy asked them in excitement as her friends nodded their heads.

"I don't know..." Sonic said suddenly, his eyes closed and his arms crossed, which surprised the rest. "You guys were in a hurry this morning, and I understand it, but c'mon guys, just giving a few seconds to Izzy to explain wasn't gonna kill you," he stated with a frown but then smiled after a few seconds. "However, you want to make it up, so... What the heck? Let's do it!" he stated with a big smile.

"Woo! This is the best T.U.E.S. Day ever!" Izzy cheered as the Mane 5 and Sonic smiled together and started music with flashing lights inside the Brighthouse, having a party together.

THE END

Author's Note

Thanks to JD1 for editing this chapter!