The manga as a whole isn't incredible but doesn't try to be. All in all, it's somewhat generic but still enjoyable.
---
The story starts off as something interesting albeit with a lot of exposition, but nothing impossible to understand. A guy forcing himself into a world of spies, interacting with his new family, and becoming stronger to keep his loved ones safe.
It does slowly start to get into ridiculousness, nothing the manga shy away from, with technology and such in a way, almost complete sci-fi. It does keep you more engaged and seems more fun that way, but I wished it still kept the spy element in play, which does especially with our male protagonist.
It does get even more absurd as these shonen-type mangas get with their powers, suddenly straying away from regular spies into superpowers which I find personally, a lazy way to a fun concept. I really think the superpowers were unnecessary, and without spoiling it, isn't all too impressive.
The manga also goes into similar to episodic stories, where you don't really see them completely connecting, but more so for character development and interactions. They're not useless but don't hold too much bearing to the heavy part of the story, making the story smooth itself into the dramatic parts rather than jump straight into it (which it rarely does, but does happen).
---
Art is enjoyable and fun to look at, it does tend to hop around a lot with changing from serious to cutesy, but doesn't make it a complete mess, which is nice. Enjoyable action scenes, does well with incorporating with their cutesy/chibi style but knows when to take itself seriously, no complaints here, really. Doesn't do anything all too amazing or revolutionary, but is still distinctive.
---
For characters, they surprisingly do it well.
We get a decently few chapters, slowly uncovering each character and dwelling deeper into their backstory, as not just a quirk of personality and nothing else, but do have their own fears and worries. The story also mainly focuses on their family, making it something I personally find cute, basically them protecting each other, worrying about another in their own way.
Albeit does get dumbed down afterward by its "comedic timing", which I find it less endearing and more so annoying after a while, basically making something dramatic into a 1900s show with "OhH yOu..!"
Again though, I need to preface that the characters aren't completely one-dimensional, even though they do have the same traits as early to late chapters, you do see them evolve in some ways.
Our female lead plays into the damsel in distress role all too often, even if they sometimes show her of being self-responsible and "strong" at times, so if the damsel in distress is an annoyance for you, this won't really change. It is definitely better done but doesn't stray away from some generic points. I personally like it though there's no romance conflict, so you won't see our male protagonist basically risking his life whilst a third wheel's going on.
The male protagonist I also enjoy. He's not shonen-level stupid. He does complain at times, but is very reasonable and tries to solve it himself without burdening his family/friends. He does protect our female lead to a ridiculous degree, but from his standpoint is also very reasonable, as she's basically always hunted, 24/7. Despite the protectiveness, he also serves as a way to see how different the spy world is, almost like a self-insert protagonist, but actually has a personality of his own.
---
Overall, I still enjoy reading this, but thinking from a critical standpoint, I can definitely see people that have read/seen far too many shounen shows/manga, they won't be impressed with the story. They might be interested in the characters and interactions, which is the most fun or the theme.
It's not an amazing manga that will change your perspective in any way, but it's still a fun read that I can recommend to some.