Matsuda's Ongoing Transmigration

After Matsuda Jinpei died, he became bound to an unknown System. It took him through space again and again, sending him to worlds that had been drastically transformed by all kinds of Mary Sues and Gary Stus, where he had to save worlds on the verge of falling apart.

At first, Matsuda Jinpei thought he had simply made a deal with the System: he would save the worlds, while the System stored up energy. Once it had enough, it would take him back to the past in his own world so he could save his childhood friend. Only later did he realize that things weren't quite as he had imagined.

Damn it! The System just wanted a worker!

If he wanted to save his childhood friend and his fellow police academy classmates, he'd have to do it himself!

After he figured that out, Matsuda Jinpei stopped letting the System manage his energy. Wasn't it better to keep it in his own hands?

Theme: Saving the world