I read this manga months ago. It's about a man who returns from an Isekai world to Earth.
I recall that just before he returns two girls from his party confess that they had a crush on him but now that he is going they are going to date two other guys from the party.
The main character tries to stay back after hearing that but the guys pushed him to the portal (I think its a portal).
After returning he finds that a long time has passed and coincidentally meets an old female friend. At first she kind of recognises him but dismisses it because he looks young.
He was a magician or saint, someone who uses magic and can now use magic in Earth too. There was also a small girl (I think) close to his female friend who can also use magic.
A long had passed since Mc left and returned back to Earth. The female friend has grown from a student to an adult. That is why she dismisses that it could not be her old friend(Mc) because Mc still looks young.