It had been five months since Konata and Kagami confessed their feelings for each other and began dating. They had been friends for years, and once there was nothing holding them back, they dove headfirst into romance. Tsukasa had tried her hardest to be supportive, but she couldn't shake the feeling that something was wrong.

The first few weeks were a whirlwind of passion. Unlike before, when Tsukasa would get to eat lunch with them every day at school, they insisted on going off and spending that time by themselves. Anytime Konata would come over to "study," there was a certain awkwardness that made Tsukasa feel like a third wheel. On one occasion she peeked into Kagami's room to find her flat on her back, arms wrapped around her new girlfriend. It was like they never wanted to be away from each other.

As the initial excitement faded, so did Tsukasa's patience. Whether she wanted it or not, she had a front-row seat to every quarrel the couple had. She had given up counting the times she sat in her room and overheard Kagami argue with Konata on the phone, wishing the walls were just a little bit thicker. It was obvious to her that just because they got along as friends didn't necessarily mean they would be good as lovers. She knew Kagami was unhappy and felt powerless to save her.

What hurt the most, though, was the jealousy. As much as she tried to deny it, she held a forbidden love deep within herself: a love for her own flesh and blood. She had yearned for Kagami for as long as she could remember and seeing her with someone else just made it worse. She couldn't even watch Kagami hold Konata's hand without feeling like her heart was splitting in half. Over and over, she would fantasize about trading places with Konata and doing those same romantic things with her sister, only to feel sick to her stomach afterwards. Kagami was the first thing Tsukasa thought about when she woke up, and the last thing she thought about as she fell asleep.

Of course, that depended on her being able to fall asleep in the first place. On this particularly cold and dreary night, an episode of insomnia was keeping Tsukasa awake. She tried to cover her ears with a pillow, but she could still hear what was happening in the next room over. Judging by the half of the conversation Tsukasa could hear, things were going from bad to worse.

"I can't deal with this shit anymore," Kagami said, sounding defeated. "We're through." Moments later, Tsukasa could hear a door opening, followed by footsteps and the occasional sob. She hid under her blanket in case Kagami came in, but nothing happened. Instead, the heart-rending sound of her cries grew louder. Tsukasa couldn't ignore it any longer; she needed to do something.

Tsukasa slowly opened her bedroom door and tiptoed down the hall in search of Kagami. "Sis, are you okay?" she called out, trying not to wake the rest of the family.

Kagami poked her head out from the bathroom, her face red. "I'm fine. Just go back to bed."

"I know that's not true." Tsukasa slowly approached, holding back her own tears. She was so used to being the one who needed someone to lean on that it felt strange to be on the other end. "I've been listening to you talk to Kona-chan all night. Please, just let me know what's going on." When they were at arm's length from each other, she put her hands over her heart. "I love you."

An awkward silence accompanied the gesture. The twins had seldom said that they loved each other, and never had those words carried as much weight as they did at that moment. That weight, though, seemed to be lost on Kagami. "Tsukasa, what are you doing?" she asked. "We're sisters. Why are you acting like this is a big confession or something?"

"Because it is!" Tsukasa cried. "I've loved you since we were kids! As more than just sisters! Seeing things fall apart between you and Kona-chan is tearing me apart because I know you deserve better." Her composure broke, and tears began streaming down her face. "I want to take her place."

Kagami closed the distance and took Tsukasa's hand. "Hey, if we're gonna talk about this stuff, let's not do it in the middle of the hallway." They retreated to Kagami's room, where they could have more privacy. As soon as the door closed behind them, they threw their arms around each other. Only then did Tsukasa realize how badly this could go for her. If Kagami didn't feel the same way, their relationship was likely damaged for good. The shame and regret hit her like a ton of bricks, and she fell to her knees, crying even harder than earlier.

"I'm so sorry," Tsukasa said between heaves while covering her face.

Kagami knelt and hugged Tsukasa again. "It's okay," she whispered. "I've got you." Tsukasa may have intended to comfort her sister, but as it turned out, they both needed to be comforted. They sat on the floor together and continued to hold each other, not saying anything for a little while.

Once she had calmed down, Tsukasa took a deep breath. "So, does this mean you accept my confession?" she asked.

"I…I don't know yet," Kagami answered. "I kind of always suspected you felt this way. We've been inseparable since the day we were born. You always clung more tightly to me than anyone else. And I'll be honest: I've had days when I wished we weren't siblings, and that you could be my girlfriend instead of Konata. But the fact remains that we are siblings. If we go down this road, a lot of people won't approve, and we'd probably never hear the end of it if Mom and Dad found out. You realize that, right?"

Tsukasa felt butterflies in her stomach. She didn't disagree with what Kagami was saying, but it hurt all the same. "I do, but…"

"Sorry, I know this isn't a good time to be lecturing you. I just have a lot on my mind. Do you want to move to the bed?"

The two slowly got comfortable between the sheets. Tsukasa scanned Kagami's face, admiring every part of it. Her deep blue eyes, tiny nose, rosy cheeks, and especially her pink lips were all beautiful. Tsukasa recalled a dream she had about Kagami when they were ten years old. She dreamt that they were walking hand in hand through a garden. They came to a stone bench, and while sitting on it, Kagami gave her a kiss. The memory of that dream came back periodically over the years, and every time, she hoped against hope that it would come true one day.

"What're you thinking about?" Kagami asked.

Tsukasa tried to come up with a lie, but she had already admitted so much that it only made sense to be honest. "How much I'd like to kiss you."

Instead of replying, Kagami brushed her hair back and moved her face close enough that their noses touched. It was Tsukasa's last chance to change her mind. She knew that what she was about to do was taboo, but she could worry about that later. She closed her eyes and gently cupped Kagami's cheeks before bringing her lips the rest of the way. It was every bit as enthralling as it had been in her dream. She felt herself drifting off into a state of utter bliss as she sank further and further into Kagami's arms.

After hearing the soft popping sound of lips separating, Tsukasa opened her eyes, still in disbelief over what had just happened. Kagami stared back at her with a face that looked like it was full of guilt. "I just…took my little sister's first kiss," she thought aloud. "That's supposed to be for someone special, and yet I…"

"Sis, you are special. I always hoped you would be my first. In more ways than one, actually."

Kagami blushed from the uncharacteristic boldness of what she just heard. "In that case, do you want to keep going?"

Tsukasa pulled her into another kiss. There was so much tension between them that it was like releasing a slingshot. Any sense of restraint was gone the moment their tongues met. Their hands began to explore each other's bodies as their clothes gradually came off. They were so overtaken by lust that they accidentally tumbled out of bed and onto the floor. The next thing Tsukasa knew, they were both naked, and Kagami had her pinned down. She had never been so turned on in her life.

"Are you sure, Tsukasa?"

"Yes. I'm all yours, Sis."