I'm Very Happy After Marrying the CEO Husband According to the Agreement - Chapter 1: Other Good Things

This is my first original novel, it may be bad, but this is all in my mind and imagination. (Warning!! There will be an Incest genre) Thank you o⁠(⁠(⁠*⁠^⁠▽⁠^⁠*⁠)⁠)⁠o(oh yeah I forgot, this cover is not mine, I just edited it, if you feel you own it and don't like me using it, please tell me)

I exist in the darkness, disappear under the bright light, and will eventually devour the sun and turn into the shadow of all things… Known by people as the indescribable terror of darkness; the king of shadows; the dark day; the existence of the shadow of the world , is still just a somewhat special high school student, facing a weird death game…

- Description from novelbuddy

Coming back from the magic world, Riya rebuked her shameless stepmother.She was back to her first life with the world treasure and thought that her life would be smooth sailing.But…What was happening with the environment?Why did the mana suddenly recover on this Green Planet?And why did those magic beasts also appear?Riya: ???Ah, Riya silently swore to secretly become stronger to deal with these magic beasts that went on rampage. She would use her runes to make a better life while watching the world recover from the destruction.Unfortunately, things were not so simple.Her best friend’s brother suddenly locked his attention on her.“Ah, ah, ah, you don't have to mind me….”“The runes you make are really interesting. Can you show me more?” The man smiled and stepped closer.“I…I can, but can you please not come too close?!”Riya just wanted to meditate silently, so how did she suddenly attract this big boss’s attention?