Let's start with the positives though. Bokutama (its short name in Japanese) is a story of reincarnation. Seven teenagers find out that they're the reincarnations of alien scientists with various ESP powers from a far away planet which got destroyed while they were investigating on the Earth, and have to come to terms with their past lives. It sure sounds like a dramatic masterpiece, doesn't it?
And it is - when it's about that. When it's about their discovering their identities - does remembering your past life mean that you are not the current you anymore? Will you reconnect with the other ones or try to deny and look at your current life? Bokutama even got some LGBT issues, which was great considering it got serialized in 1986. Enju decides to reincarnate as a male, Issei to be forever close - as friends - with her past love Gyokuran, even as just friends. And they are friends, as his reincarnation, Jinpachi, is male... but hetero. The former can't repress his feelings and is still in love with the latter, even if it is an impossible love as Issei was not loved even when he was Enju.
The art is gorgeous, if you're into old artstyles. There's a lot of detail (sure, not as much as modern shoujo manga) and even double spreads of space and stars can get emotional considering what they mean in the series. The problem is with the two main characters - Arisu, in the past called Mokuren, and Rin whose previous incarnation was Shion.
Arisu, our MC and supposed to have more traits than just "girl", with it being a manga written by a woman, is dumb as a brick - a squirrel may have a higher IQ than her. She is sixteen and after an accident where Rin regains the memories of his previous life, gets with him... a seven years old. A kid who along who manipulates everyone after regaining his memory (and his ESP powers) back.
He manipulates and gaslights the same Arisu he is supposed to love along with everyone else, pretending to be Shukaido, a character who got reincarnated into Fuyuhiko - as Shion was dark skinned and got black hair as the latter, while Shukaido was blond and light skinned like Rin - by blackmailing him. We see his backstory - he suffered a lot, but comes off as mostly just... edgy, even then.
Do note that him being edgy is not be a problem, actually! He's hot, no denying that. A typical handsome tsundere & edgy boy that we all love. (well, maybe not all. Personally I do.)
Expect that his past doesn't excuse the one thing that completely ruins a 10/10 masterpiece and makes you throw it away, disgusted.
That is, the romanticization of rape. Shion rapes Mokuren, and it is clearly described - you can't deny in any way what it was. You may expect Mokuren/Arisu to get with someone who loves her instead like Gyokuran/Jinpachi instead of her abuser, who hates her during all the story and "deflowers" her (she is seen as pure and sacred because of her particular powers that make plants grow), but nope. We are supposed to see it as a good thing and forgive him because of his tragic past. Gokuren is even happy afterwards (while screaming <<No!>> and <<Stop!>> the whole time) because now she is "human" and not pure anymore.
Some may be able to ignore the rape and pedophilia, and in general how toxic those two's relationship is as she gets manipulated in both lives. I can't, and it's even sad because it excels in everything else. Arisu realizing how wrong this was, not falling in love with her literal abuser would make you say "okay, it got such themes but they're clearly shown as bad". Instead, in the sequel she and Rin were respectively twenty-four and sixteen when their son and new protagonist was born. Yeah.
