Before starting with Shingu, I was unable to help noticing how every critic seemed to agree that OP was poor. So it was quite a surprise when the OP turned out to be a very decent school song with Ghibliesque visuals. It may be marred a bit by Muryou's placid mug, but otherwise it's great. I find it a good match and preview for the show.

There's a low-quality copy at Youtube for those who want to listen for themselves.

I guess that SDB started it with: "The OP and ED royally suck", in a separate item, no less. Then everyone in his halo started aping it. Not all is readily googleable, but here's Ubu's opinion: "Worst. OP. Ever. " (yep, with the <strong> tag).

I'm not saying that all these people are deaf and blind, they just have a different taste. A part of the explanation may be that Shingu's OP is not a "blockbuster" type OP to which fans are conditioned by the likes of Xenoglossia and Stellvia. I saw EDs done with a similar bend, I think. Perhaps Abenobashi is an example. But I cannot recall a similar OP.

One thing that bothers me about Shingu's OP is a strong deja-vu. I feel like I heard it before, but cannot quite remember where. My own school didn't have a school song, so, most likely, it's an anime-induced memory. Strangely, it has a smell of something out of one of Hanaukyo Maid Tai versions, but neither of them features a school song. Anyway, it's odd.