I Confessed My Love, Then My Yandere Sister Took Me Home

[One heroine + yandere + pure love + extremely sweet, no angst] After Gu Ruoxu confessed to the class beauty, Su Han, and was rejected, a red-robed celestial maiden descended from the sky and rescued him from the awkward situation. But why did the red-robed celestial maiden look more and more like the person Gu Ruoxu liked? And had he kissed her while drunk? The two cleared up the misunderstanding from years ago, and just as they were growing closer, Gu Ruoxu discovered Lin Xiran's hidden secret. Was the person he liked really a yandere? And had she even imprisoned him? Should he accept the status quo and embrace the love meant only for him, or ask the cops for help? It was a choice. Only, the first one to start acting strange was Gu Ruoxu himself?