If you liked the Red Garden anime, the Anime-Planet community thinks you'd like:
What happens when authority and consequence are removed? When the inmates truly run the asylum. On the spaceship Ryvius there are those who would fight for order, and many more who would fight to destroy it. Love, hate, anger, greed, avarice, and perhaps hope are the fuel for the Ryvius, and only one can save those who call it home...
Both Infinite Ryius and Red Garden are strongly character-driven shows. While they both have a strong plot and mysteries that need to be resolved, in the end everything is about the characters. The plot and mysteries really exist so that they can develop and change.
Has someone done something to hurt you or the ones you love? Are you seeking revenge? Rumor has it that there’s a website that can service your needs. Titled “Hotline to Hell”, it contains a form that can be accessed only at midnight. Type in a name, and the Hell Girl will carry out your bidding – for a price. For though your appetite for revenge will be satisfied, your soul will also be condemned to hell after you die. But who is the Hell Girl, and does she care whether your revenge is justified? Apparently not, as long as she gets more souls…
Murao Mima has created a robot daughter named Key, but after raising her for a very short time, Mima dies, leaving behind cryptic messages telling Key how she can become human. Key must struggle alone to learn the harsh lessons of life and search for the 'key' to her own dream: the power of 30,000 friends to make her a real human girl.
If you like anime with a plotline that is obscure and cryptic, and only comes clear over time, while retaining a strong sense of characterization, then you'll be happy to know that these are the common traits shared by Key the Metal Idol and Red Garden. Another feature of both these anime is a nebulous and threatening enemy which proves difficult, if not impossible, to get a grip on, let alone defeat.
Guided by a star only they can see, a group of maidens known as HiMEs have begun to gather at Fuuka Academy. These young women have been endowed with dangerous supernatural powers that they can use to their heart's content, but there's a price: to wield them, they must put their most important thing on the line. Now, in the midst of school work and friendships, they find themselves caught in the midst of strange conspiracies seemingly related to the terrifying monsters that attack them. Is the power of the HiMEs strong enough to save themselves and the ones they love?
Red Garden and Mai-Hime are two dramas that masquerade as action series. Each focuses on a group of characters all but forced into fighting foes they are told little about, and eventually become as pawns in a larger plot. Both series pays a good deal of attention to each of its characters, who in both shows wind up facing impossible dilemmas towards the end. Red Garden is certainly more down-to-earth compared to Mai-Hime's explosive powers and attempts at comedy, but that's the only major difference separating these two shows. If you're a fan of one, the second should make for a very good choice.
Ouri is an orphan who was raised by Keisei, a man he considers to be his older brother. One night, Ouri finds a strange wounded girl in the temple of the orphanage. Cold and covered in scars, Ouri initially thinks that she is dead – that is, until a mysterious talking cat tells him that she is a Shikabane – a corpse. After secretly watching Keisei heal the girl without explanation, Ouri decides it's time to leave the nest. However, he has picked a poor time, and he soon realizes that he's tangled in a strange, supernatural web. Why does Ouri continually meet this girl as she hunts monsters? What does Keisei have to do with it all and what exactly is her mission?
Shikabane Hime and Red Garden are both tales of girls who have died, been brought back, and must now fight monsters for a secret society in order to end their undead state.
They are both fairly serious in tone, with plenty of drama, a decent plot and character interaction. I am sure if you enjoyed one you will like the other.