#reian

It seems that at the beginning of the main story, Rei was always going to help Anzu achieve her revolution with Trickstar since that role was originally what Keito had tried to plead Rei into doing in Crossroad. Rei refused, being unwilling to throwaway his own dreams to be burdened by the problems at Yumenosaki. With Anzu, it was probably mixture of not really understanding and wanting to protect her new found “home” with Trickstar, but she was willing to shoulder their burdens and self-sacrifice everything for the idols. This was exactly what Rei lacked and the guilt from letting things progress as they did, would always have lead him toward her. 

Rei and Anzu are also surprisingly similar in some ways, being that they’re both very well loved by others. Rei was so popular that Keito grew up with a bit of an inferiority complex toward him and Anzu was so popular that actual idols were starting to think she could sell as an idol herself. This popularity extends to each other since Rei seems to be very fond of Anzu too, with Kanata asking Rei whether his “wonderful smiles recently” were due to Anzu and Rei replying that it was thanks to her and that she is “like a miracle”. Presumably Anzu also cares about Rei since she stayed with him during the Flower of the Rainy Season scout story despite having other pressing work to attend to. And we all know how much Anzu loves her work. 😌 

In Rei’s !! idol story, he talks about how they’re all worried about Anzu’s innocence being taken advantage of by others with ulterior motives. But by the end he suggests that his warning in itself might be to lull her into a false sense of security so he can take her for himself so she should be more careful. This is a bit of a common theme for him since ! so its hard to know how serious he is about “locking Anzu up for himself” but let’s just say it’s probably a safe bet that if he wanted to he probably could. 😏 The rest of UNDEAD (cough Adonis and Koga cough) have taken it upon themselves to protect Anzu from Rei as well so they know the risk. Notably in the School Festival event, Rei uses Anzu’s compliment that he suited the butler costume well to rebut Koga, which may imply jealously. He goes even further and invites Anzu to stay the night in his coffin with him. 

From what I’ve gleamed from the stories, it seems like Rei also finds Anzu attractive saying that he “might become charmed” if she was too close to his face and that she looks like a “delicious meal wrapped up beautifully”.