How Can Saving My Adoptive Sister Count as Cheating?

The main story is complete. Bonus chapters are ongoing. Sato Yu wakes up one day to find that he has transmigrated to Neon, a world where Neon ACG culture is still underdeveloped. Looking into his background, he finds his parents are dead, he has no car or house, and all he has is a little stepsister with a terminal illness and a cat-loving System that benefits her at his expense. [Make anime to earn fame points and cure your stepsister in stages.] "Huh? You want to trick me into becoming a plantation slave in the anime industry? With this world's pathetic entertainment scene, I could just copy a few light novels from my previous life and make a fortune, then stroll right to the top of the world!" She's just a stranger, a stepsister with no blood relation to me. You expect me to put all this effort into saving her?" Sato Yu scoffs at the impractical System. But... this little stepsister cooks for him, wielding her slender, pale hands over the wok. She calls him "Onii-chan" in a sweet, tender voice, full of affection, and warms his bed for him on cold winter nights. Small but dependable, frail yet strong, and so adorable that anyone would want to do anything for her. Defeated by this girl, Sato Yu smiles wryly and activates the System once more, his gaze firm. "For my little sister, I have no choice but to do it." "Become an anime master!"