I thought I'd write a new review for this manga, since an anime adaption is on the way, and the other reviews are a few years old. I'll begin with a short spoiler-free summary, and then move into a deeper review.

Summary:
Mairimashita Iruma-kun! is a fun school-life style comedy. The art style is somewhat simplistic, the comedy lighthearted and innocent, and the characters are bold and likable. The story is comprised of short arcs, episodic in nature, and there is little to no overarching plot. Characters still maintain the development they received during said arcs, however, so all good. Recommend for a light read, lots of potential for the future. 9/10

More in-depth (still mostly spoiler free):
Story: 8
As mentioned previously, Mairimashita Iruma-kun is a comedy manga, and a school-life manga; however I was pleased to find that it is somewhat free from the more annoying tropes associated with the pairing. No major harem plot or perverted misunderstandings here; just a school-life finally free from the ecchi tag. The arcs occasionally follow the typical school-life formula, but just as occasionally deviates.

There is little to no overarching plot, however this does not hinder the manga significantly. Characters who learn and develop as they go maintain their development as the manga progresses, giving a sense of time passing within the story. World building is slow, but consistent, and hints are dropped at a larger, overarching story in the works for the future.

Art: 8
Art is consistent and well-proportioned. The art style is is somewhat distinctive and soft in areas In coloured pages, characters are often well-defined by singular, distinctive colours. Expressions are well-drawn and evoke emotion. The art could be better however, as it is a little simplistic at time, and uses a lot of blocking.

Characters: 10
Characters are simplistic, bold, and likable. Even the villains are enjoyable to watch, and every character is distinctive from each other. Despite being simplistic in design, the characters are often expanded upon gradually.

Enjoyment: 10
This part is more a personal opinion, and I think this part is heavily dependent on the person. Some may think that the lack of consequence-heavy conflict is boring; I however, enjoyed this manga as a light read quite a bit.

Overall: 9
A well-rounded manga driven by excellent characters and lighthearted humour that works well in the supernatural, school life and comedy genres.