Mu Chen arrives in Date A Live with a System, thinking he'll get a harem, a peaceful daily life, and invincibility. But unexpectedly... (This isn't a harem or a woman-collecting story. Maybe I'm different from other authors! I won't steal Shido's harem! Not a single girl! The protagonist's stats can be modeled on Emiya.)
Mu Chen: "System, what features do you have?"
System: "A shop, missions, cultivation techniques, a golden finger..."
Mu Chen (overjoyed): "I'm rich! I'm rich!"
System: "I can't do any of the things I just mentioned."
Early the next morning...
"Selling a System! For only 998! You can't lose, and you can't get ripped off..."