My girlfriend is a magical girl!

When it comes to summer, it is youth, love, the Shura field, the crystal sweat beads shed by young and beautiful girls in the sun, and the shy appearance of girls.
Lu Ming thought so, but there are such lovely beings as magical girls in this world, and they are his childhood sweethearts.
[In 2030, you became the devil who destroyed the world. Even the strongest magic girl 'Deep Blue' was no match for you. You defeated her, but then you realized that she was your childhood sweetheart who you had lost contact with after graduating from high school. Her diary was stuck on the day you parted ways with her. She liked you.]
[It is better to restore the relationship with your childhood sweetheart, reward: XXX]
Lu Ming is a little confused. He is in high school now. Isn’t your system a little too early?
Well, since we are childhood sweethearts, there is nothing we can do.
But as time passed, Lu Ming found that there seemed to be more and more magical girls around him, and... why did it feel like a Shura field.