Issei took Mash to a late lunch downtown and later to the museum. They spent time walking around town and even bought some clothes for Mash. When Mash asked why Issei only replied with, "Well you're probably going to be staying for a while since we're not sure how to go to and from Chaldea yet." Mash seemed to understand where her Senpai was coming from. For all she knew she was stuck there, although she didn't mind that at all.

As sunset approached Issei led Mash home, he intended to introduce the girl who had such a large impact on his life to his parents. He looked to the side and saw Mash fidgeting nervously. Issei put his hand on her back to calm her and gave her a warm smile.

"Don't worry. I told them all about what happened to me while I was away. To be frank, they have been wanting to meet you for a long time. You'll be fine."

Issei reassured her and Mash seemed to relax a bit. They made it home and were stopped in front of the door.

"Ready?" Issei asked.

Mash took a moment. She looked at Issei and did something not even she expected. She kissed Issei on the lips. It took him completely by surprise, he didn't expect that from her. She took a deep breath. "Yes, I'm ready."

Issei took a second to recover from the surprise kiss then opened the door and led Mash inside.

"Kaa-san! Tou-san! I'm home!" Issei announced as he came in.

"Welcome home Issei. How did it go?" Issei's mother asked from the kitchen.

"Nothing bad happened right?" Issei's father asked from the living room.

"Well, things were complicated in the beginning but, well things worked out. In fact I have someone for you to meet." Issei said while holding Mash's hand.

There was a moment of silence as it seemed that both Issei's mother and father stopped what they were doing. Suddenly there was scrambling in the other rooms as the pair came into the front hall. There was surprise on their faces as they saw their son holding hands with a girl a bit shorter than him who had an intense blush on her face, while their son had a beaming smile.

"Is she..?" "Could it really be?!" The pair couldn't hide their surprise.

"Tou-san, Kaa-san, I would like you to meet Mashu, my girlfriend." Issei said with pride while Mash's face turned an even deeper shade of red.

Mash managed to recollect herself somewhat and removed herself from Issei's arm.

"Good afternoon Senpai's parents. I'm Mash, Mash Kyrielight. And this little one is Fou. It's a pleasure to finally meet you." Mash politely bowed with Fou on her shoulder.

The Hyoudou pair were stunned for a moment but then suddenly Issei's father seemed to realize something.

"Wait. Isn't that the name of the girl who you were with in the other world?" His words seemed to make his wife realize this as well.

"Yes, this is her. Like I said, things started off complicated. Let's go into the living room and I'll explain."

After he said that they all went to the living room and Issei explained about how the letter was a trap set by a fallen angel and how he summoned Mash to help fend her off. After that the devils from his school came and chased the fallen off and how they set up a meeting tomorrow to exchange information. The parents had a grave look on their face, clearly upset that someone tried to prey on their son's desires in order to kill him. They hoped this event didn't permanently scar their son from trusting anyone who shows interest in him, but from the look on his face as he was standing next to Mash it didn't seem to be a problem at the moment.

The pair bowed their heads deeply to Mash. "Thank you so much Mash-san! Not only did you protect our son when he disappeared but you also saved him again from what was essentially an assassination attempt. There are no words to truly express how thankful we are!"

Mash shook her head. "I'm the one who should be thankful. If it weren't for Senpai I would have died a long time ago. Even when his memory was gone he still did his best to help everyone. He went beyond what any human could have and because of that everyone was saved. In all honesty I should be apologizing on behalf of Chaldea for essentially kidnapping your son." This time Mash bowed her head to the parents.

The two stared at Mash a bit then smiled. She is a really good girl. They both thought. They were happy their son met someone like her.

Issei's mom put on a mischievous smile and addressed the girl.

"Hey hey Mash-san, it's ok if you start calling me Okaa-san."

Mash immediately sat up straight and started blushing again. Jumping in with the momentum Issei's father said his piece as well.

"Then you can call me Otou-san as well, and we'll just call you Mashu."

Mash didn't know how to respond and looked to her Senpai for help. She was met with a slightly blushing Issei who clearly couldn't hide his happiness. He looked at her. "See? I told you there was nothing to worry about."

As things were starting to heat up they were all suddenly interrupted.

"He-krzzrt-an anyone hear-kzzrt." Something that sounded like a broken transmission was coming in. The Hyoudou pair were confused and alarmed but Issei and Mash looked at each other, able to figure out what was happening. Issei created a magic circle with his hand and deactivated the bounded field around his house that blocked communications from coming in and out through magic. With that the signal cleared up.

"Mash! Can you hear me? Come in! What's the situa- oh, seems everything is fine." A hologram appeared in the living room and on the display was Da Vinci. The parents were even more confused but Issei was the first to respond.

"Hey Da Vinci-chan. Long time no see. How have things been?" Issei asked casually.

Da Vinci gave Issei a wry smile. "Things have been hectic around here since you defeated Goetia. Lots of paperwork and interrogations."

"Don't you mean interviews?" Mash asked.

"No." Da Vinci said with a smile that clearly indicated that she didn't like the talks she had with the Mages Association.

"But never mind me. What was happening to you Fujimaru-kun? My readings earlier indicated you were in trouble." Da Vinci said with concern.

"It's a bit of a long story." Issei then explained what happened just like with his parents before.

"I see. Well at least things worked out in the end. It looks like that battle was the catalyst you needed to reconnect with us."

"Those were my thoughts exactly, but the question is where do we go from here?" They all sat in thought until someone spoke up.

"Uhm, sorry to interrupt your meeting but would you mind introducing your friend to us Issei?" His mother interjected. Issei laughed, embarrassed that he forgot that his parents were in the room.

"Right, sorry. Tou-san, Kaa-san, this is Da Vinci-san, the other person from Chaldea that I told you about who helped me a lot."

Da Vinci bowed to Issei's parents. "It's a pleasure to finally meet you. I am Leonardo Da Vinci, but you can call me Da Vinci-chan." She said with a wink and a peace sign.

Issei's parents greeted her in return.

"Our son told us about you but it's still hard to believe that you are "the" Leonardo Da Vinci considered, well…" Issei's mom was referring to Da Vinci being a woman.

"It's been a while since I got that reaction. It's fine, I am the real deal but I figured, instead of coming back as a crotchety old man I would take the form of the most beautiful thing in the world. And what could be more beautiful than the Mona Lisa." Da Vinci puffed out her chest to display how proud she was about her decision.

"We just finished thanking Mashu but we would like to extend our thanks to you and all your staff for taking care of our son." Issei's mom continued.

Da Vinci had a complicated expression. "Well it's no problem but…"

"Mashu already told us about how he got there and we forgive you all. It was an accident and in the end our son became stronger for it. So we'll let bygones be bygones." Issei's father interjected.

Da Vinci gave a grateful smile and turned to Issei.

"I see where you got your kindness and understanding from Ritsuka-kun."

Issei had a bit of a shy smile on his face from that compliment. However Issei's father had a question. "I've been meaning to ask, why do you call Issei Ritsuka?"

Issei was the one to answer. "I mentioned to you before when I was transported I lost my memory, which included my name. So they gave me an alias until I remembered it, which was Fujimaru Ritsuka. By the time I got my memory back so much time had passed that I got used to being called that and even though I told them my real name I also recognized the name they gave me as my real name too. So I said they can keep calling me Ritsuka."

The parents nodded in understanding at their son's words. But now that the pleasantries were done they had to refocus on the problem at hand.

"So, what should we do?" Mash asked.

"Well we should establish a summoning zone for you so that we send reinforcements to aid you. On top of that we need to create a way to travel to and from, not only for you but for Mash as well."

Issei was confused. "Why for Mash as well?"

"She didn't rayshift to get to your location, rather it seems you summoned her like someone would summon a traditional servant."

Issei was surprised by this revelation. "But I thought you needed a catalyst to summon a servant. Not only that, Mashu is a Demi-servant, I thought it didn't work the same for her?"

Da Vinci shook her head. "I don't know. I don't have enough data to know the reason yet. The only thing I really have to go off of is the fact that Mash became a servant thanks to you and you two have a strong connection. The thing that gets me the most is the matter of what the catalyst could be."

[I know what the catalyst is.] Ddraig spoke for everyone to hear.

"Hello Ddraig, how are you?" Issei's mom addressed the dragon happily.

[I'm the same. Thanks for asking.]

"You know what the catalyst is?" Da Vinci asked, surprised.

[Yes. It was acquired during partner's battle with Goetia.] Issei was surprised yet again at the new bombshell. I picked something up at the Temple of Time? [After we thought Mash died, partner used her shield to fight Goetia, and when he dealt the final blow the shield dissipated into magic particles. When that happened, partner unintentionally absorbed some of the magic into the Boosted Gear. In other words, Mash's shield is a part of the Boosted Gear now.]

Everyone was stunned at what they were just told. Da Vinci nodded in understanding. "I see, then with the catalyst absorbed by Ritsuka-kun along with his magic and strong bond with Mash he was able to do a successful servant summon without the help of Chaldeas." Da Vinci was in contemplation.

"It's good that we figured this out but we're getting off track." Mash said, trying to get back on topic.

"Right, sorry. Is there anywhere where we can set up a summoning circle?" asked Issei.

"I'm not detecting any ley lines near you but there is a ton of magic around you."

"Yeah, that's my doing. Once I came back I laid runes all over town for me to use just in case. I especially set runes in and around my house as well as a bounded field to protect it from the supernatural, which was why you were having trouble contacting us earlier."

"I see. Then in that case it may be possible for you to create a pseudo ley line in your own home. You just need a place to put it."

"We have room in the basement." Issei's mother said.

"That would be the best way to keep it secret, right?" Issei's father followed up.

"That works. In that case once that has been set up I have a few requests for the first ones you should send to help me."

After that Issei and Mash set up the magic circle in the basement. Da Vinci told them that it would take time to stabilize and should be done by the end of tomorrow, but for now she would continue to run diagnostics. Issei's parents led Mash to a spare room and Issei brought the things they bought on the date to her new room. Everyone was exhausted from all the excitement of the day so they all retired for the night.

Issei lay in his bed going over the crazy day he just had. He had been tricked by a fallen who tried to kill him, reunited with his Kouhai, met and set up a meeting with the devils, gone on a date with Mash, brought her home to his parents, and re-established contact with Chaldea. All in all, one hectic day.

As he was beginning to drift into sleep he heard a knock on his door. "Come in." Issei said.

The door opened and Mash was there in her nightwear. She nervously moved in the room. "Senpai, if it's all right. Can I sleep with you?"

Issei was frozen. His Kouhai kept on finding ways to surprise him, and it had been less than a day. He shook his head to get out of his daze then responded. "I-if that's what you want." He couldn't keep his voice from slightly shaking.

Mash closed the door behind her and laid down next to Issei. She moved herself so that she could wrap herself around Issei's left arm. Issei was having a hard time keeping himself calm. His old personality was screaming at him to take her here and now while his current personality was doing its best not to scare her off.

While Issei was having this inner dilemma Mash spoke to him. "I'm sorry Senpai."

"What for?"

"I did a lot of things today based on my own feelings and didn't give you a chance to say yes or no." Issei was wondering what she was talking about but she continued. "I kissed you without asking, you bought clothes for me because I needed some, and you and your family provided me a room out of the kindness of your hearts. I should have-" She was interrupted by a kiss on the lips from Issei. She was surprised but melted into the kiss. Issei broke off the kiss after a minute.

"You're overthinking it Mashu. Remember, I was the one who introduced you as my girlfriend. Nobody made me do it, I did it because I meant it. I want to be with you Mashu. Although maybe I should be apologizing since I didn't ask if that was ok with you." Mash had tears forming in her eyes but she was truly happy at what Issei said. "This might sound ridiculous but I think it might have been fate that we met. The time I spent away when I returned home was truly lonely for me. We have been through so much, I couldn't just move on from it."

"I felt the same. Even though it was less time for me, I felt it when you left. Chaldea felt so empty without you, and while I tried to keep myself distracted I couldn't help but want to see you as soon as possible."

The two were pouring out all of the emotions they had bottled up. Then Issei decided to make the next move. "Hey Mashu." He brought her in close. "Why don't I show you just how much you mean to me?"

He locked eyes with Mash seeking her confirmation. Mash stared back processing what Issei said until finally her entire face turned red. If one looked closely you could swear you'd see steam coming out of her head. Finally she responded once she got over her embarrassment. "If it's with you then I don't mind." She said shyly.

Issei was celebrating in his mind but kept his cool. He didn't want to mess up this moment, that was important for both of them. Needless to say neither of them got much sleep that night.

So as you can see, I decided that the main girl is going to be Mashu. This story is still a harem story so the others will still get their time to shine but I want to create a special dynamic between Mashu and Rias seeing as how Rias originally takes charge as the main girl in the relationship but now Mashu is in that spot. Also I saw a comment asking for Issei x Mash and was like "What did you think was gonna happen?" like it wasn't obvious they would end up together. Also I saw another comment about the power of the servants in comparison to the world of DxD. For reference Artoria has Excalibur and the noble phantasm is basically a nuke. I'm pretty sure that makes her at least on par with someone like Sirzechs in terms of power and there are plenty of servants who are stronger than Artoria even if we exclude the divine and god class servants. Things won't start evening out until (Spoiler alert for Highschool DxD) Issei gets a new body from Great Red and Ophis. Last thing. In terms of what servants he has, I'm operating under what events are currently going on IRL on FGO and past events as well. At the time of writing this the FGO 5th Anniversary is just starting so unless a servant is specifically tied to the plot of something later on like B.B. or Caster Artoria Issei will have them. (The only exception to this rule is Skadi because I have an idea for her later on in the story.) P.S. If you see me use a servant that should be story locked in my story it means that I didn't know they were story important because I haven't gotten that far yet in the main story. I'm on Shimousa right now in game and have been trying to keep myself only vaguely aware of the future plot points.