That Flower in the Spring

I've been living my life following instructions
"You have the power to proceed," said my teacher as he gave me a star pendant, and looked at him in the eye.

In order to save humanity, I have to go back to the past....
That is in the 17th Century where I have to meet and stop a certain person

But what if,
the person of my past lives in the present?

"Jiro-kun, why are you here?"

That I need to protect?
But I'm already intertwined with the future?

"I'm here to protect you, just rest!"

Yet my mission is at stake?
"Your body can't bear it any longer, Will you go back to that time?"

Which one should I choose?

In this world, all I want is for everyone to be safe