The Unrewarding Days of Demon King Alrilia

An ordinary (self-proclaimed) high school girl, Yuki Inoue, saves a little girl who is about to be hit by a truck—and dies in the process. Thinking she's dead, she closes her eyes, but when she wakes up, she's been reborn as a baby in a different world. She vows to finally find happiness this time around... but wait? Her mother was killed? What? I'm the Demon King? Kill people? No, no, no... Let me just escape from here and live freely! That's how she enjoys life in this alternate world. She tries to enjoy it, but things don't go smoothly...? (*Since this is written on a whim, the settings are loose. There are sudden developments and convenient plot devices. It's basically serious, and people do die. If you have time to kill, I'd be happy if you'd read along.*)