Practice Partners, Not Bed Partners! Ladies, Don't Cross the Line!

[Multiple heroines + heroines chasing the hero after losing him + a battlefield between the young ladies + everyday life]

After Ling Ze dies and transmigrates to a parallel world, he awakens the [Born Sparring Partner] System and starts with limitless spiritual energy, but he's unable to use it.

Later, he signs eight-year sparring contracts with four young ladies. Over the course of those eight years, he trains each of them into a magical prodigy, but they nearly work him to death in the process.

When the eight years are up, he prepares to run, but they refuse to let him go. They wage a battle for the chance to have Ling Ze as their sparring partner...

Tsundere catgirl: “If you come back and train with me... I'll even let you use me as a toy, meow...”

Cool, aloof vampire girl: “Just let me have one bite, okay? I'll do anything!”

Cool, mature female executive: “Little bro, your big sister is begging you so nicely. Aren't you coming back? Don't blame me if I have to make you~”