One-shot.

Disclaimer: Hello dear readers! I recently watched made in abyss and read the manga, and immediately fell in love with the series! I'm very fond of the pairing Reg X Riko! I tried finding some fanfics for this couple, but couldn't find any. Maybe I wasn't looking hard enough. Anyway, I don't own made in abyss. I hope you enjoy this one shot!

Reg watched Riko with worried eyes as he watched her guide Nanachi in making their dinner for the night. The events that had transpired were still fresh on his mind. He clenched his fists. 'I swear, I won't let anything happen to her! I'll protect her with my life!' Reg thought, determined. Riko could feel Reg's eyes on her, and turned towards him to find him staring intensely at her. She then sweat dropped, and turned towards him.

"Um, Reg? Is something wrong?" Riko questioned. Reg blushed at getting caught for staring at her. He then shook his head.

"N-no, nothing's wrong." Reg stuttered. He then mentally beat himself up for stuttering. Riko giggled. She then turned back towards Nanachi.

"Dinner will be ready in a bit." Riko informed. Reg nodded, and resumed at staring at her. Nanachi then started to serve the pieces of meat that were drizzled in a sweet and sour sauce. Reg looked at the food with hungry eyes. He then took a bite, and his eyes gleamed at the taste. He then turned towards Riko.

"This tastes great!" Reg exclaimed. Riko giggled.

"I didn't cook it, I only guided Nanachi in making it." Riko admitted. Reg shook his head, and took another bite. When Nanachi took a bite of their meal, their mouth watered. Nanachi then gobbled down the food, and started to choke. Reg gasped, and handed Nanachi a cup of water. Nanachi grabbed the cup of water, and downed it. They then sighed, and looked at Reg thankfully.

"Thanks, na." Nanachi thanked. Reg nodded. He then continued eating his own meal. After they finished the meal, Riko offered to wash the dishes. Reg looked at the wound on Riko's arm, and shook his head.

"I'll do it!" Reg offered. Riko looked at him, and smiled.

"Thanks!" Reg blushed at Riko's smile. He then grabbed the dishes, and started washing them. Nanachi watched the encounter between Reg and Riko, and smirked. They then walked up to Reg.

"So, what's your relationship?" Nanachi questioned. Reg looked at them in confusion.

"What do you mean?" Nanachi sighed.

"I mean between you and Riko. Are you two lovers or something?" Reg blushed at Nanachi's question. He then started fiddling with his metal thumbs.

"I-it's nothing like that! S-she just means a lot to me is all. We're friends, and I promised everyone back on the surface that I'd protect her." Reg explained. Nanachi nodded.

"Ah, I get it. She's your treasure. It's like how Mitty was to me, I treasured her very much. Like I said before, you'd better take good care of your treasure." Nanachi told. Reg nodded. Nanachi then snickered. "You know, you looked really pathetic when you were crying out Riko's name, na." Reg blushed in embarrassment. He then faced away from Nanachi. Reg finished washing the dishes, and walked over to Riko, who was sitting down and looking at her wound. Nanachi walked over to them. "You know, you've been asleep for about two days. I recommend that you take a bath." Riko looked up at Nanachi, and nodded.

"Yeah, I will. Where's the nearest bathing area?" Riko questioned. Nanachi beckoned for Riko and Reg to follow them.

"I'll take you to a place that I like to use for when I'm hurt." Nanachi told. Riko and Reg stood up, and followed Nanachi into a forest like area that seemed to glow all around them. When they arrived, Riko looked around in awe.

"Wow! This place is amazing!" Riko exclaimed. Riko then turned towards Nanachi. "Is it really okay for me to bathe in here?" Nanachi nodded.

"Yep, I've used this place plenty of times. It's safe." Nanachi assured. Riko nodded, and attempted to untie her sling, but couldn't do it. She then turned to Reg, who was sniffing the water.

"Sorry Reg, but I can't get this off by myself. Give me a hand." Riko told. Reg dropped the water that was cupped in his hands in surprise, and turned towards Riko with a massive blush on his face.

"O-okay!" Reg agreed. He then stood up, and began to untie the sling. Once the sling was off, he hovered his hands in front of Riko's dress. "Riko, raise your arms a bit." Riko did as told, and raised her arms. Reg's blush deepened as he pulled down her dress. He then quickly turned away as Riko turned towards him.

"Ne, are you going to go in?" Riko asked. Reg blushed.

"I-I'm just going to keep watch!" Reg claimed. Nanachi grinned.

"Go on and get in….Sometimes blood sucking insects come to have a bite~ And you're pretty good at chasing those things away." Nanachi stated. "I'll keep watch." Reg blushed as he thought about it. 'Blood sucking insects!? I can't let those things touch Riko! *Sigh*, I guess I have no choice.' Reg slowly started to get undressed, and put Riko's arm around his shoulders, and put his arm around her waist to keep her balanced. They then slowly stepped into the glowing water. Riko smiled in awe as she looked at the water's colour change from a turquoise colour to a bright yellow when she touched the water. As they descended into the water, Riko's foot slipped, but Reg caught her. His hand rose a little too high, and he blushed as red as a tomato. Reg quickly brought his hand back down, and steadied both him and Riko. Riko sighed in relief.

"It's kind of slippery, huh." Riko stated. Reg nodded.

"Be careful." Reg told. Riko smiled.

"Wherever we go, the colour dissipates around us!" Riko exclaimed. She then smiled in awe as a school of fishes swam around her pelvic region. "Reg, look! Even though the water's hot, there are small fish swimming around in here!" Reg blushed as he faced away from Riko. He then started to feel a warm feeling in the pit of his stomach. 'For some reason…I feel thirsty.' Reg thought. Riko then held her arm and hissed in pain.

"Ouch! O-ow." Riko hissed. Reg looked at her in alarm.

"Riko!" Reg called. Riko shook her head.

"I-I..I-I'm fine…the hot water just stung a bit." Riko admitted. Reg continued to give her a worried look. Riko smiled at him. She then looked down, and her eyes widened. Reg gave her a confused look.

"Hmm?" Reg questioned.

"Reg…what's up with your penis?" Riko questioned. Reg looked down in confusion, and blushed so hard at what he saw was going on with his lower region.

"Gyahh!" Reg cried out as he dove underwater. 'W-what's going on!? W-what's this feeling?' Reg questioned. "I-I don't know. This is…This is…Irredeemable!" Reg cried. Nanachi raised their eyebrow at the two kids.

"Hmm? What's with you two? You're really still fickle about this?" Nanachi questioned. Reg and Riko looked towards them. "Reg, come on. You've already kissed her, right?" Nanachi then started making kissing noises. "Kissed…" Reg blushed, and stood up waving his hands about, trying to signal Nanachi to shut up. Nanachi only grinned at him. "No point in getting embarrassed now." Riko looked at Reg in confusion.

"Reg, what's this kiss thing about?" Riko questioned. Reg's blush deepened, and he took a step back.

"Uh, that was…" Reg gulped. "That was hardly called a kiss…" Reg drifted off. He then looked towards Nanachi with an angry look. "Nanachi, you coward! You get in here too!" Reg shouted. Nanachi looked at him with fake ignorance.

"What are you talking about? I'm on lookout duty here. So, go ahead and take your time in there~" Nanachi sang. Riko grabbed Reg's arm, bringing his attention back to her.

"What's this about a kiss?" Riko questioned. Reg blushed, and pulled his arm away. He then stepped away from her, refusing to look her in the face. Riko frowned, and tried to face him. "Hey, come on." Reg then swam away from her. Nanachi watched in interest. They then sighed.

"Jeeze, I can't bear to watch this.." Nanachi sighed. They then saw Riko hold Reg from behind, preventing him from leaving. Nanachi watched them. 'Mitty, thank you for pulling Reg's treasure out of that place.' Nanachi thanked. "A bit more, I hope you can wait for me just a bit longer." Nanachi muttered. Reg blushed as Riko was pushed up against him with her good arm around him.

"Finally caught you!" Riko exclaimed. Reg sighed. Riko then put her face near Reg's. Reg blushed at the close approximate. 'T-too close!' Reg thought as his blush deepened. "So, what's this about a kiss?" Riko questioned. Reg sighed. 'I guess I have no choice but to tell her.' Reg inhaled, then exhaled.

"A-alright. Y-you see, when you were poisoned, I did what you told me to do! B-but you fainted, and eventually stopped breathing." Reg explained. Tears then appeared at the corners of his eyes. "I-I got worried about you! But then Nanachi showed up, and told me to perform CPR on you. S-so, I did." Tears poured out of Reg's eyes. He then turned around, and hugged Riko, surprising her. "I-I was s-so worried!" Reg cried. Riko's eyes widened. She then smiled, and held Reg's face in her palm. Reg looked at her. Riko then wiped away his tears with her thumb, and rested her forehead on his.

"I'm sorry for causing you so much trouble." Riko apologized. Reg shook his head, and hugged her tightly.

"I'm the one who should be saying sorry. I didn't protect you!" Reg cried. Riko smiled at him. "I'm a terrible partner! I didn't protect you to the best of my abilities! I failed you, Natt, Shiggi-" Reg rambled on. Riko rested her lips on his, silencing him. Reg's eyes widened. Riko then pulled away, and grinned at him.

"You didn't fail anyone! I'm here because of YOU! It's thanks to you that I even survived for this long!" Riko claimed. Reg blushed. Riko then hugged him, and rested her cheek on his. "I'm very thankful to you, Reg. I'm glad I met you." Reg smiled, and hugged Riko back. He then nuzzled into Riko.

"I'm glad that I met you too." Reg admitted. He then looked at her. "I'll stay by your side forever." Riko grinned at him. Riko then shivered, and leaned into Reg for warmth. Reg wrapped his arms around her. "Are you cold?" Riko nodded. "We should probably get out of the water then." Riko nodded. They then made their way towards the bank of the spring, and climbed out. Nanachi dropped down form where they were perched.

"So, you two finally done?" Nanachi questioned. Riko nodded while Reg stared at Nanachi in realisation. A huge blush then spread across his face. 'N-Nanachi was there the whole time!?' Nanachi looked at Reg, and snickered. A tic mark appeared on Reg's head. He then shook his fist. 'They're mocking me!' Reg thought. Riko tried to dry herself off, but was having a difficult time doing it. She then turned to Reg.

"Reg, I'm having a hard time drying myself off. Can you dry me off?" Riko asked. Reg's blush hit the maximum, as he slowly nodded. He then shakily grabbed the towel from Riko, and begun to dry her off.

AN: Hello! I hope that you enjoyed this one shot of Reg and Riko! I absolutely adore this couple! XD I did feel a bit awkward when I wrote the word, um, penis. I'm still new to the fanfic society. Anyway, I hope that you'll all read some of my other fanfics! See ya!