I dunno if it's just because I've read too much stories...bur I found this plot too typical.The characters seems to have no distinction and while the writing itself is not bad and it is stable, there are no particular part that make it different than the other similar stories. The emotional part of characters are simply not there... Like when MC got his past lifes memories, he should have more reaction to it such as fear, shock, confusion, and who am I? Ren? Or am I *blah past lifes names*? And, another thing is even when he accept the past lifes memories, if a child got memories out of nowhere they will be influenced by it. It will create trouble. The personalities of his past lifes will not be easily resolved like you seemingly written.
