The first volume of Spica of Sin and Punishment is, with no hyperbole, one of the best manga openings I have ever read. It is a perfect twist opening. Beyond that, Spica of Sin and Punishment is a fun episodic thriller that I recommend if you're into that genre like I am. Each arc is its own self-contained mystery and so far they've all been enjoyable in their own way. There's hints of a bigger narrative building up, but it's too early to comment on that. Also, despite the premise, it has a far more lighthearted tone than you would expect. Spica so far is a greatprotagonist. I would best describe her as a manipulative ruthless murderer who is simultaneously a decent person. She's the perfect lead character for this kind of episodic mystery/thriller. Aside from her, the male lead(?) Tohakari is fun. He's essentially a chuuni who larps as a serial killer, but is really a good kid. Think Kyoutarou from The Dangers In My Heart, except he's in a thriller instead of a romcom.

Let me finish off by saying that, despite the overall positive tone of this review, I have very mixed feelings on Hajime Inoryuu as a writer. I think he is very, VERY good at making unexpected twists that keep your attention and make you want to keep reading. He is not so good, in my opinion, at crafting an cohesive overarching narrative around those twists. I think My Dearest Self with Malice Aforethought is a good example of that. Despite that, I still do recommend Spica of Sin and Punishment. I think (hope?) that the more episodic format he's going for here will play into his strengths as a writer rather than his weaknesses. You can get away with wild out-of-nowhere twists when it's confined to an insular story arc a lot more easily than in a more serialized narrative like Malice Aforethought. Only time will tell, but I am looking forward to seeing how this one plays out.

Also the art is good. I should mention that too.