When I Was In My Third Year Of High School, The System Asked Me To Defeat The Demon King?

[Campus] [Daily] [Funny] [Love] [Relaxed] [No Violence] [Extraordinary]
[Preface: The beginning of everything, please use holy water to treat the saint who is affected by the evil spirit, and talk to the saint. 】
Shen Nian looked at his sister who was drinking yogurt and fell into deep thought.
You mean, my sister is a saint and yogurt is holy water?
[Main mission 1: Brave young man, become an adventurer! Reward: New adventurer. 】
【Side mission 1: Find the cute cat! Reward: 1000 gold coins. 】
Shen Nian: "No, I'm in my third year of high school. Which buddy from another world has the System tied to me by mistake?"
Wait a minute, will there be a gold coin reward for completing the task?
Can the title also add attributes?
Is there such a good thing?
——
(Original title of this book: "Stop it, old enemies cannot become wives!")
(Mainly focused on abstract daily life on campus, not a slap in the face.)