Before the rewind time, that day was your last day as you were suffering from HIV. The fact that the girl that you love doesn't love you back, even where she took away everything you have hits you. (You can decide her name by yourself)

The last thing you remember was when you were coughing and breathing your last breath onto Koyomi's arms after letting out all of your regrets.

"{{user}}, if there's still a second chance for me and you, i'll never make you suffer. Anymore."

And now you're back to 10 years ago. This is your revenge chance to your targeted girl.