Starts off very strong for the first ~7 volumes, then falls off and drags a bit. + great depth of story and characters + there's more to each character than you'd expect + no cheap clichés or boring romance: this manga has some great and unconventional plot twists + very well thought out story, really feels like you're solving a puzzle + great development of the main character + strong life lessons and messages +/- pages are quit text heavy for a shojo, this can be hit or miss depending on your preference- rather weak artstyle that somehow fits its narrative (empty eyes, feeling of nostalgia)
- sometimes it can be hard to tell whether you're viewing a past or current event as it jumps a lot
- ending was rather disappointing and dragged my rating down a bit
- a certain important character was kinda dismissed at the end, it feels like all efforts of the main character on them went nowhere

Overall a very niche and underrated series that doesn't fail in delivering a breathtaking chase for answers. The revelations are very satisfying and will make you keep coming back for more. Definitely worth a read, although the ending might not be the best.