Keisuke was getting tired of the constant dodging and attacks. As much as he loved his sister, and hated seeing her being used like this, he just had to wonder where she got this sudden power-up. 

It must have been Soranaki, he deduced, his eyes once again glowing grey.

That just fuelled his determination to break his sister out of Soranaki's spell.

The plan he had in mind had been inspired from Doki Doki Precure (he had Touma to thank for that introduction, despite how girly it seemed), in which Makoto sang a song to Regina. He really liked that scene, since it really touched his heart. 

And now, he was going to recreate that scene. 

Only with Touma as Makoto and his sister as Regina. 

Luckily, Micchy was either really really determined to make up for his idiocy (Keisuke doubted that part, since Micchy was sort of delusional) or he was really scared of Keisuke (Keisuke doubted that as well. He wasn't THAT scary, right?), because he managed to set up everything quickly, tossing the microphone to Touma too before running off. 

Keisuke shouted, "YOU CAN DO IT TOUMA! I BELIEVE IN YOU!" 

Touma gave him a determined nod. Then he turned to face Natsume. 

Natsume... you showed me the light in my heart... 

You're the reason I managed to fight against Rasen... 

You're the reason I could get the Ogre watch... 

For that... I thank you... 

That's why... I won't let Soranaki hold you back anymore. 

No more. 

Touma gripped the microphone tightly. 

Keisuke called out to Akinori and Ayame, "Stall her! I'll help Touma!" 

"Got it!" The 2 nodded before they attacked Natsume as Keisuke jumped to the stage and rushed to the keyboard, "Ready for this?" 

Touma nodded. 

Keisuke smiled, "Good. Let's give this all we've got Touma!" 

"AH!" Touma grinned back before he made eye contact with Natsume. 

Keisuke began playing the song, his fingers light but quick while Touma took in a deep breath. 

Hitorikiri de fuan na yoru Uta wo kuchizusamu no Furuesōna kurayami demo Chikara ga waku kara

Natsume felt her heart begin to thump a bit. W-What's this feeling?.... I-I'm supposed to be devoted only to Master! Y-Yet... This song... 

Kotoba to onpu hitotsu hitotsu ga Maru de kiseki no kakera Hamingu sureba Sharara hirogaru Sore wa mirai e hibiku merodi

Keisuke smiled as he continued to play the melody. 

Natsume backed away a bit, confused over what she was feeling right now. 

Her old memories began flying in like doves. 

She began to remember.

Kokoro wo komete watashi wa utaou Koe wo todoketai haruka kanata made Ano hi no yō ni kibō tomosu Furēzu wo habatakasete 

Natsume's eyes began to water as she remembered who they were. 

The strings in her heart started to unravel. The chains began to break hearing Touma's sincerity as he walked to where she was. 

Touma....

Akinori and Ayame watched with smiles on their faces. Keisuke grinned. 

Kokoro wo komete issho ni utaou Kon'na ni hiroi sekai no katasumi Afuredashita namida sae mo Itsu no hi ka kagayakasete

Natsume's tears fell freely now. With every tear, the potion she drank fell too. 

Soranaki had overlooked a VERY VERY important detail about the potion. 

The potion had a weakness in the form of sincerity. 

Also, the strings he put on her were not permanent. 

In fact, Soranaki hadn't known that that spell could be broken. 

Negai wo nosete asu mo utaou Daijina hito ga soko ni iru kagiri Kinō wo yori mo motto mabushī Sono egao ni mata aitai kara

As Keisuke started to play the ending, Touma, who was now in front of her, smiled at her happily while holding out a hand to her. 

"Come on, Natsume. You're much more stronger than this. I know that," Touma stated. 

Natsume's eyes widened, before they softened into a smile as she took the hand. 

Everyone cheered seeing this.

Then, caught up in the moment, Touma kissed her on the lips. 

Keisuke could only chuckle seeing his sister blush to no end, while Ayame did the same to Akinori, who was a guppy. 

Keisuke smiled. 

We did it. 

We brought Neechan back.