Series: Miracle on a Winter street (kuyagiyu)

https://tieba.baidu.com/p/4192272290

A koReimu was miraculously born out of dying parents and is saved and adopted by a miss. But after she grew up she betrayed miss by marrying a stray who plans to take over Miss' home. Miss kills them and their children to make sure nobody else made the same mistake as her (adopting a stray orphan)