Rokujouma no Shinryakusha!? Volume 25 Discussion

Koutarou and Maki are out establishing a base for them after having taken the space port, Theia's giving aerial support and not too happy about it, Koutarou and Maki end up having a conversation about the reasoning for the army not attacking and she says the third reason is him. Theia gets annoyed that they're chatting when she's essentially on overwatch, Koutarou tells her that her being angry is a waste of her beautiful face, so she acts angry and leaves them to it.

They get back and Koutarou goes straight to Harumi and Clan. She seems fine overall but is still unconscious, they all meet up for a 'serious' talk. Clan locks the door and says about how important it is that no-one else knows.

Revealed that Harumi is actually Alaya, because it was originally designed to have the person who unsealed it use it and the lack of life force wouldn't be a problem (the life force is needed to amplify the magic).

Koutarou is obviously rather upset at that and gets somewhat angry at Clan, Kiriha calms him down and completes the explanation. Essentially ~70% of her life-force is in the sword, and for want of a better explanation, essentially attracted her soul after she died, making her reincarnate near the sword. That being the origin of the eternal youth myth.

Turns out the healing will only work for Koutarou now and to help her, they either have to remain together forever or sever the contract. They make the decision to wait until Harumi is awake and then get her to sever the contract.