I adore DASH. I bought this when I was 16 or so (5 years ago) on a whim based on how the first few pages left me excited to read more, and I've never regretted it since, which is different from how I feel about most of the BL purchases--although most are decent--I've made in the past couple of years now. It's one of the few manga that I can reread every year or half-year or even three months or so. I even wrote an even more detailed review of it once upon a time when I was really excited to spread its name, but for now I'll just say this:
DASH! is, I've always felt, a BL manga with the feeling of shounen sports manga, except, of course, with a focus on homosexual romance instead of a young man's iration for his upperclassman and naught else. It has all the energy of that kind of manga, and more, considering Akimoto--the main character's--guy-ish (it's hard to describe another way, but large lovable dork works) but loyal personality. It basically takes all the best parts of senpai-kouhai interaction in a shounen sports manga and places it into a BL setting wherein the kouhai (Akimoto's) iration for his upperclassman develops into love, well-done especially for the three or four chapters the manga-ka manages to do this in. I've seen a good amount of BL with sports as dressing or generally part of the story as a device to have its love interests interact more, but most of those tend to drift towards slice of life, or something else I'll elaborate on in a moment.
Saitou, the guy Akimoto ires, is part of the reason the feeling of "shounen sports manga" really works in this BL--he's dedicated to judo, and has incredibly determined (and receptive; he's not cold or anything) personality, but that personality isn't a device for Akimoto to make "deredere" for him; it's a part of his character, and his determination actually holds meaning within the story. Unlike a lot of BL protagonists' love interests, his feelings are hard for Akimoto to discern in a way that readers would be familiar with--Akimoto is close to him, but still doesn't know him well enough, and much of DASH! is his taking the time to find out more about Saitou as a person--find out about his feelings on the life he's living now, his frustrations, and so on. Saitou really isn't the type to just blush his feelings away at every touch until those feelings somehow turn into "love," at all.
That's the other thing--aside from many BL manga with sports as a part of it falling into "slice of life (and romantic feelings)," many others easily fall into the "seme" and "uke" dynamic without a care for the proper build-up, and particularly, evolution, of relationships. That's excusable, of course, since much of yaoi genre's focus is on a ionate relationship between men that eventually leads to sex.
But the reason why I love this manga in particular is the reason I love to ship male characters in a lot of shounen manga--because it takes the time to strengthen their relationship as people, (and, though this is more of a shoujo thing--) as well as love interests, and puts them on a more or less equal footing with each another because of that. It's not an original take as much as a refreshing take on senpai-kouhai in a sports team falling in love in high school, largely for the energy and development of its protagonists.
That said, it's not a perfect manga (and the one-shot in the middle is fairly typical; I liked the dreadlocked friend, I think...I'm pretty sure it had a guy with dreadlocks...), and I may have been gushy considering how much I love its managing to weave the camaraderie of guys in sports shounen within an original BL story (i.e., not doujn) as well as having fun main characters who change for the better as they continue to interact with each other, since that's basically my favorite things put together, but I've not found one like it outside of said doujinshi since, so I hold it pretty close to my heart. It's one of Natsume Isaku's best, and I think she's very fond of it too, since she used its title in a newer work of hers, Ameiro Paradox, as the name of the magazine that its protagonists write, photograph, and bring scoops for.
Also, as a note--although the summary refers to Akihito as Saitou's "slave," it doesn't hold the usual smutty baggage that comes with yaoi manga, and in the same vein, I think a lot of people complained about Akihito being referred to as Saitou's 'gopher' in the original June translation, which makes sense in context but sounds silly nonetheless--as they changed it later to, he's more of a "servant"--a kouhai who fetches stuff--for Saitou at first.
