Bokutachi Otokonoko
It's about childhood friends questioning their feelings for each other...also, quite funny.

Aoi Hana if I do remember correctly, been a while since I read it

Kagi About boy who have crush on his best friend but don't wanna tell him because it will destroy their friendships.
Off*Beat
Me Niwa Sayakani Mienedomo
Shinkuu Yuusetsu
Ashita Hare Nochi Inu Youbi 17 page long. Very adorable stories about 2 boys are lover and their dog.
Donuts Tsuushin don't for get to check the manga-ka works she wrote other BL and Shoujo ai stories. They may look young but I'm sure there no shotacon or lolicon in it.
Junjou de Wagamama na Kare I not sure why it's labe as yaoi, because didn't see an yaoi in it.
Edith (Anthology) only one chapter so far.
Boku wa Sakana
Bokura ni Matsuwaru Etcetera

Also if you have money on hands and can understand little japanese then you should buy
Unmei no Aite desu ga, Nani ka?Maki Akane practices to the tea ceremony , he really can not stop thinking of of a boy that he meets . Back when he was young he gets reoccurring dream, that he is princess who married man that that closely resembles the other boy who he meets at the tea ceremony -

And for Shoujo ai, I have to go with Aoi Hana there also anime base of it too. To make more safer it's done by woman so you don't have to worried about ecchi part because there none. 🙂

I would also like to mention Usagi Otoko Tora Otoko.
It's one of the sweetest ones I've read. Definitely recommended! 😃

Hmmm...I keep finding more titles to add here XD

Koori no Mamono no Monogatari , Silver Diamond , Sayonara no Riyuu , Hikari no Machi , Hatsukoi no Yamai , Geinoujin na Yatsura , Kuro Otoko , Lost Boys.
All very chaste - they never go past kissing, and the guys involved respect each other very much.

Hanamatsuri is to BL what Cotton is to GL - only subtext, little to no actual romance. So of course, it's very pure and quiet.

Oh - and I haven't read this one 'cause it's yuri, but Girl Friends probably fits.

Aoi Hana is okay, but it's terribly melodramatic. The romantic melodrama really ruins the purity of the story and I gave up after a while. But of course, if you like that sort of thing...
Imho, Sasameki Koto does a much better job with the schoolgirl GL setting.

Just as an FYI, Koi no Hanashi ga Shitai (suggested by akari_mizunashi) shows the sexual side of their relationship from the get-go, so I dunno whether I agree on its purity factor...

Maybe Golden Days - but the BL is one-sided. The other guy really cares about his friend, but not in the romantic sense.

The Mainichi Seiten! series is weird in that the relationships are often pure, but go through moments where the purity is rather questionable (though never actually 'impure' per se). You have to read it yourself to see what I mean ^_^

Makeinu no Nandemoya is another odd one. Is it really even BL at all? Kind of questionable, since nothing at all happens in the actual time-line of the story, even though something is implied to have happened in the past...

Otome Cake is on my to-read list, and it looks nice - though fairly typical.

Edit - Just read Otome Cake...I like it, and the love is quite pure; but most of the stories are about girls who have one-sided crushes on their straight friends...So, while I don't think the entire volume fits this request, be sure to at least read the 4th chapter (Tiger Lilly) - it's very nice.