Since there is no review about this yet, I'll give it a go.
This is a fast-paced, (probably) rather short and lovey-dovey romance story between the two characters Koshino and Mizukawa. There is no big drama yet, and the main characters don't have any super special and unrealistic features to them (like being the most popular, beautiful, etc.). If you enjoy following 2 people being cute together, you'll probably like this.
The story felt a bit weird in the beginning. Basically, Koshino falls in love with Mizukawa and more or less immediately confesses to him. Mizukawa agrees to date her, even though he didn't even
know her name at that point (lol). After that, the chapters mostly consist of spending time together at school, home, dates, including the usual stuff like birthday and valentines day. In those 16 chapters which are out so far, roughly a whole year passes, so it's pretty fast paced.
Koshino is a first year (later on second year) student at high-school. She's cute, very open towards others and pretty squirrely. She seems like the kind of person who's always smiling. She fell in love head over heals for Mizukawa and is always eager to make him happy and spend time with him.
Mizukawa is a second year student with a rather cool character. He's basically the opposite of Koshino; he's calm, sometimes a bit sarcastic and less open towards others. But at the same time he really puts effort in making her happy and also showing (and telling) her how he feels about her over and over again.
How do you imagine your ideal relationship? Possibly good communication, reassurance, affection, and making happy memories together? Mairimashita Senpai checks all of those. This manga has one of the best, strong, and healthy relationships I've seen in a manga or anime.
The story is fast-paced compared to many other romances. The two characters get together right from chapter 1. Usually, there's the "chase" or a confession many chapters later. But this manga is like, "You wrote cute song lyrics on my desk, I like you, so let's date" within a day. The story focuses on their relationship and how they handle different situations like Valentine's Day,
amusement park date, being at home together, etc. There are plenty of sweet moments in the series.
The art is very fitting for a shoujo manga. I like that quotable dialogue, Serina's inner thoughts, or times when they are together, get a big placement on the page. Some of the art looks beautiful and memorable.
The relationship between the two characters is very strong. Other shoujo mangas have insecurities in the relationship because of misunderstandings or jealousy. However, this couple openly talks about their problems and how they're feeling at the moment. They work out their concerns which many relationships fail to do. They both reassure each other all the time in how much they like one another. As for physical affection, characters do the right amount of teasing without being forceful.
I think the only problem is that the characters aren't particularly special themselves. Like you only know them on the surface-level. Also, the side characters are there but don't matter as much; later on, they will be. Looks like that's where the manga is headed.
I looked forward to reading each chapter. I like the cute dynamic between the characters. The manga has teasing moments like a little fanservice which I liked. Overall, you will like this manga if you want to read about a great relationship. Not sure how realistic this is but you can learn from it or dream about it.
There is nothing really exceptional about this series except for the artwork, which is rather nice, but isn't unique. Not much about this series is unique at all and the characters are banal and uninteresting, but that may just be this manga's power. It's believable and I can see middle school and high school girls being able to relate to this manga. This manga clearly tries to play up to what they think the emotions of an excitable incoming high school girl hoping for a deep teenage love story are like.
There has literally been no original plot here, each chapter is the typical fare
of the genre: Valentine's Day, Summer Vacation, White Day, Amusement Park Date, Going Over to Each Other's House, Friend's Crushes, School Festival, Skipping Assembly, Movies Date, etc. There are also no arcs or anything like that, each chapter is basically a one-shot with a banal plot that just sets the stage for some quotable, fluffy moments for the couple.
There are much better entries in the High School rom-com genre to spend your time reading, to be honest. The only thing I can really commend this manga on is that the relationship is non-toxic and unexpectedly mature for their age, and is a good model for young couples in high school to follow. No over-over-over-protective boyfriends. No overly-insecure girlfriends. No physical violence. There is trust and growth. Cute, sweet, fluffy moments. Boy doesn't pressure the girl to do "H-things". No emotional blackmail or sexual abuse. No cheating.
One thing I am so happy to have been deprived of is the hackneyed bullying trope. I am so glad the girl isn't conveniently homeless either, or that the guy is conveniently rich. They are very ordinary and as real as it gets, which may be this manga's power after all.