Honestly, I have never been so bored with a show before. I don't know how I managed to finish it.

* The storyline was dragging on and on, and I had the feeling that nothing much happened at all. I even drifted off during later episodes. The thing is, I do not mind slower paced series, if -- IF -- it fits the storyline. Also, twelve episodes of basically the same over and over again gets boring whatever the content might be. The plot could have been tightened to maybe four episodes or so.
* The writer seems to have only a passing idea of how the music industry, cafés or workplaces in general work. Examples that annoyed me most: Sentences like "Now that you are debuting, you are a real artist!" (or something like that), an employee mopping the floor during opening hours without reason, taking breaks just ecause you want to, "trainees" that practice unsupervised and are something like eleven years old(?), a freelance composer who then has to got to Shanghai (?). Overall, it feels as if the writer was one of those "trainee" children.
* The camera work was uninspired and kind of static.
* The acting was stiff, which was most apparent in group scenes, where those actors who did not have something to say just stood around like mannequins.
* The sets showed the tight budget, and putting a rainbow flag doesn't improve things. Although I did like the colour scheme they chose.
* Other people have already commented on the band's musical abilities, which I cannot remark upon, since I myself have no abilities in this field whatsoever. I don't think the pink-haired guy's singing was very good though.
* If the story is about tasty coffee, then I want to see tasty coffee! We haven't even seen how Plengrak brews it -- show us how the grounds look like when the water is poured into the filter, at least. The director responsible should maybe look at some Japanese shows who excel in showing food and drinks and make the audience crave them.

All in all, I'd say to give this series a miss.