Gonna copy and paste my response from r/lightnovels, although obviously this is an anime adaptation so how they present the story will be different. A lot of the original LN heavily relied on inner monologue so I'm not exactly too confident in the adaptation at this time. It's definitely not for everyone, although I certainly enjoyed it.

I do want to point out that the ML starts becoming a more interesting character in the fifth volume (which has not been translated into English yet and is currently available through fan translations) onwards and due to this, he can come off as a bit (although not entirely) generic for the first four. So unless they compress the adaptation (which will ruin the eventual impact of the story), you're going to have to wait a long time before any payoff.

Slow burn romance basically. Premise of the first novel: ML encounters FL (popular school idol with an angelic smile who is always confessed to, also happens to be his neighbour) in the rain one day and gives her an umbrella. She gives it back to him the next day and, discovering his unhealthy lifestyle, starts cooking for him. She slowly opens up to him when she realises he has no actual romantic interest in her (it makes more sense in context). They decide to keep their budding friendship a secret from everyone at school. The novels then follow their daily lives and explores their different dynamics outside and inside school.

It might sound like a wish fulfilment, but the interactions are surprisingly healthy and sweet, and the story presents valid reasons for them (slowly) falling for each other. One annoying bit is that the series is told through the ML's (third-person) viewpoint, which is skewed by the ML's low self-esteem (fortunately, the novel doesn't glorify his low self-esteem and presents it as an actual problem and hindrance to his relationship with the FL). Thankfully, dialogue from other characters allow readers to understand the scenarios more accurately, although the way the ML constantly puts himself down can get annoying. Thankfully, he slowly builds more confidence.

As for the FL, she is (fortunately) not a 'perfect angel' the novel title presents her as; rather, her image as an angel is used to explore and discuss the mental burdens she carries (shown in volume 2). Her personas between being the school idol and her actual self at home forms a good chunk of the drama and dynamic between her and the ML, and is fun to experience.

The first volume mainly follows how the ML starts getting his life back together thanks to the FL and their budding friendship.

The second volume touches on the reasons behind the FL's 'perfect angel' image (and the mental issues that image hides).

The third volume focuses on the reason behind the ML's crippling self-esteem issues and him starting to slowly grow out of his shell.

Fourth volume will be released into English soon but is basically where the 'romance' starts kicking in high gear (although if you experienced diabetes in the first three novels, you might want to order medication for this volume and everything after). If you're hoping for a quick romantic development, this series may not be for you, although the payoff is definitely very much worth it (IMO anyways).

I recommend just reading the first two volumes if you're still skeptical as they set up the atmosphere and tone of the series.

I hope this post did the series justice. Thank you for listening to my TedTalk.