I watched ReLIFE in early 2019 and I had the manga on my favorites on manga rock for quite some time. I finally decided to read it this month and the manga is even better then the anime.
The anime is fantastic but the manga had so much more content and made me tear up as much as the anime did. There was so much more character development that you could see in the manga and not in the anime. Also I preferred the manga ending then the anime ending. The ending is somewhat the same its just they shorten the content that was put in the anime
I loved the chibi drawings at the end of the chapters and loved that the entire series is colored. Never read a manga series that is fully colored

This is a series you need to read and watch, it is 10/10