The Devil's Good Girl - Chapter 28: Now, you even lecture your mother.

One morning, after being bound to the system, MC started his routine of always being captured/ attacked by the ML.

“What the fuck? What is going on? Have I completely lost it?”

As I stare panicky at the dot unable to decide what to do, the white dot disappears and a line of text appears in its place.

[Installing files. 1% done…]

As I watch the text in shock, the percentage gradually increases. […2%...3%...4%...]

I move to the living room in a zombie-like manner, too shocked to think clearly and lie down on the couch.

“Something is wrong with me; I think I finally lost my sanity…”

[…12%...13%...14%...]

Unable to affect the situation in the least, I stare dejectedly at the percentage increase, while my mind starts exploring the possible explanations. In the end, as the percentage hits 90%, I narrow it down to three possibilities.

The first possibility is that I am in fact still unconscious and this is all a product of my mind. I pinch myself and whimper at the pain, as in my nervousness I used almost all my strength.

Nope, the first is out.

The second possibility is that I have completely lost my mind and am suffering from delusions. Hmm, I cannot exclude this, but while possible, I don’t think that this is it. The only thing out of the ordinary is that fucking line of text.

The third possibility …

[Installation successful!]

The text disappears and a new message appears in my eyes…

The third possibility … is that I gained a system. I read the message with my mouth agape at the implications.

[Welcome user, to the Perverted Daddy System!]

Fuck…

It’s said that the prince of virtue had almighty martial arts. It’s said that the prince of virtue had the most handsome appearance in the world. It’s said that the prince of virtue was brilliant. But all was legend! A fire ruined his wonderful appearance and his legs. Even the talented bride under their marriage agreement were replaced furtively. Ye Liu-li was his bad-luck substitutive princess. She went a long way to graduate from Medical University and had her internship with pain and joy. Who knew that in order to save a suicide patient, she fell off the building and crossed time into a “chessman” of prime minister. She had also been married to the disabled prince replacing her elder sister. On the wedding night, when most other couples were having their romantic night, she was thrilled. It didn’t matter. Revenge never came too late. She would never let go of any of them who entrapped her or harmed her.

- Description from Novelupdates

Side story of Kyoukai Senjou no Horizon bundled with the first press release of the 1st, 3rd, 5th and 7th Blu-ray volumes of both seasons of anime.

This side story follows Asama, Kimi and Mitotsudaira aboard Musashi one year before the beginning of the main story, as Asama is considering to create a music band together with her two friends for the next festival in Aki, a territory under the governance of K.P.A. Italia.